diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/NotificationController.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/NotificationController.java
index 284c8f81..627972ad 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/NotificationController.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/NotificationController.java
@@ -10,6 +10,7 @@
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
+import javax.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort.Direction;
@@ -36,14 +37,14 @@ public QueryNotificationListLatestResponse queryListLatest() {
     @Operation(summary = "FCM 토큰 등록")
     @ResponseStatus(HttpStatus.CREATED)
     @PostMapping("/token")
-    public void registerFcmToken(@RequestBody RegisterFcmTokenRequest request) {
+    public void registerFcmToken(@Valid @RequestBody RegisterFcmTokenRequest request) {
         notificationService.registerFcmToken(request);
     }
 
     @Operation(summary = "즉시 푸쉬알림 발송")
     @ResponseStatus(HttpStatus.CREATED)
     @PostMapping
-    public void sendInstance(@RequestBody SendInstanceRequest request) {
+    public void sendInstance(@Valid @RequestBody SendInstanceRequest request) {
         notificationService.sendInstance(request);
     }
 
@@ -69,21 +70,22 @@ public void deleteByNotificationId(
     @PostMapping("/experience")
     @DisableSecurity
     public void sendInstanceToMeBeforeSignUp(
-            @RequestBody SendInstanceToMeBeforeSignUpRequest request) {
+            @Valid @RequestBody SendInstanceToMeBeforeSignUpRequest request) {
         notificationService.sendInstanceToMeBeforeSignUp(request);
     }
 
     @Operation(summary = "예약 푸쉬알림 발송")
     @ResponseStatus(HttpStatus.CREATED)
     @PostMapping("/reservation")
-    public void sendReservation(@RequestBody SendReservationRequest request) {
+    public void sendReservation(@Valid @RequestBody SendReservationRequest request) {
         reservationService.sendReservation(request);
     }
 
     @Operation(summary = "예약 푸쉬알림 시간수정")
     @ResponseStatus(HttpStatus.OK)
     @PatchMapping("/reservation")
-    public void changeSendAtReservation(@RequestBody ChangeSendAtReservationRequest request) {
+    public void changeSendAtReservation(
+            @Valid @RequestBody ChangeSendAtReservationRequest request) {
         reservationService.changeSendAtReservation(request);
     }
 
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/ChangeSendAtReservationRequest.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/ChangeSendAtReservationRequest.java
index d7338db2..530c5495 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/ChangeSendAtReservationRequest.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/ChangeSendAtReservationRequest.java
@@ -3,10 +3,12 @@
 
 import com.fasterxml.jackson.annotation.JsonFormat;
 import java.time.LocalDateTime;
+import javax.validation.constraints.Future;
+import javax.validation.constraints.NotNull;
 import lombok.Getter;
 
 @Getter
 public class ChangeSendAtReservationRequest {
-    private Long reservationId;
-    @JsonFormat private LocalDateTime sendAt;
+    @NotNull private Long reservationId;
+    @Future @NotNull @JsonFormat private LocalDateTime sendAt;
 }
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/RegisterFcmTokenRequest.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/RegisterFcmTokenRequest.java
index 1b6b21c1..18c46a36 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/RegisterFcmTokenRequest.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/RegisterFcmTokenRequest.java
@@ -1,11 +1,11 @@
 package io.github.depromeet.knockknockbackend.domain.notification.presentation.dto.request;
 
 
+import javax.validation.constraints.NotBlank;
 import lombok.Getter;
 
 @Getter
 public class RegisterFcmTokenRequest {
-
-    private String deviceId;
-    private String token;
+    @NotBlank private String deviceId;
+    @NotBlank private String token;
 }
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendInstanceRequest.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendInstanceRequest.java
index 60bc9b40..949c33db 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendInstanceRequest.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendInstanceRequest.java
@@ -1,13 +1,14 @@
 package io.github.depromeet.knockknockbackend.domain.notification.presentation.dto.request;
 
 
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotNull;
 import lombok.Getter;
 
 @Getter
 public class SendInstanceRequest {
-
-    private Long groupId;
+    @NotNull private Long groupId;
     private String title;
-    private String content;
+    @NotBlank private String content;
     private String imageUrl;
 }
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendInstanceToMeBeforeSignUpRequest.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendInstanceToMeBeforeSignUpRequest.java
index 30907c8a..30e8f75c 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendInstanceToMeBeforeSignUpRequest.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendInstanceToMeBeforeSignUpRequest.java
@@ -1,11 +1,13 @@
 package io.github.depromeet.knockknockbackend.domain.notification.presentation.dto.request;
 
 
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotEmpty;
 import lombok.Getter;
 
 @Getter
 public class SendInstanceToMeBeforeSignUpRequest {
 
-    private String token;
-    private String content;
+    @NotBlank private String token;
+    @NotEmpty private String content;
 }
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendReservationRequest.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendReservationRequest.java
index dcb5077a..87f8bdec 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendReservationRequest.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/notification/presentation/dto/request/SendReservationRequest.java
@@ -3,13 +3,16 @@
 
 import com.fasterxml.jackson.annotation.JsonFormat;
 import java.time.LocalDateTime;
+import javax.validation.constraints.Future;
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotNull;
 import lombok.Getter;
 
 @Getter
 public class SendReservationRequest {
-    private Long groupId;
+    @NotNull private Long groupId;
     private String title;
-    private String content;
+    @NotBlank private String content;
     private String imageUrl;
-    @JsonFormat private LocalDateTime sendAt;
+    @Future @NotNull @JsonFormat private LocalDateTime sendAt;
 }
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/reaction/presentation/ReactionController.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/reaction/presentation/ReactionController.java
index f19ff7de..21d4a440 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/reaction/presentation/ReactionController.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/reaction/presentation/ReactionController.java
@@ -6,6 +6,7 @@
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
+import javax.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.DeleteMapping;
@@ -29,7 +30,7 @@ public class ReactionController {
     @Operation(summary = "알림에 리액션 등록")
     @ResponseStatus(HttpStatus.CREATED)
     @PostMapping
-    public void registerReaction(@RequestBody RegisterReactionRequest request) {
+    public void registerReaction(@Valid @RequestBody RegisterReactionRequest request) {
         reactionService.registerReaction(request);
     }
 
@@ -38,7 +39,7 @@ public void registerReaction(@RequestBody RegisterReactionRequest request) {
     @PatchMapping("{notification_reaction_id}")
     public void changeReaction(
             @PathVariable("notification_reaction_id") Long notificationReactionId,
-            @RequestBody RegisterReactionRequest request) {
+            @Valid @RequestBody RegisterReactionRequest request) {
         reactionService.changeReaction(notificationReactionId, request);
     }
 
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/reaction/presentation/dto/request/RegisterReactionRequest.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/reaction/presentation/dto/request/RegisterReactionRequest.java
index 08183da0..1969fde5 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/reaction/presentation/dto/request/RegisterReactionRequest.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/reaction/presentation/dto/request/RegisterReactionRequest.java
@@ -1,11 +1,11 @@
 package io.github.depromeet.knockknockbackend.domain.reaction.presentation.dto.request;
 
 
+import javax.validation.constraints.NotNull;
 import lombok.Getter;
 
 @Getter
 public class RegisterReactionRequest {
-
-    private Long notificationId;
-    private Long reactionId;
+    @NotNull private Long notificationId;
+    @NotNull private Long reactionId;
 }
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/relation/domain/repository/CustomRelationRepositoryImpl.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/relation/domain/repository/CustomRelationRepositoryImpl.java
index 45e0521d..a7ddcb80 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/relation/domain/repository/CustomRelationRepositoryImpl.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/relation/domain/repository/CustomRelationRepositoryImpl.java
@@ -34,14 +34,14 @@ public List<Relation> findFriendList(Long userId) {
     @Override
     public Optional<Relation> findRelationBySendUserIdAndReceiveUserId(
             Long sendUserId, Long receiveUserId) {
-        return Optional.of(
+        return Optional.ofNullable(
                 queryFactory
                         .selectFrom(relation)
                         .where(
                                 relation.isFriend
                                         .eq(false)
                                         .and(friendPredicated(sendUserId, receiveUserId)))
-                        .fetchFirst());
+                        .fetchOne());
     }
 
     @Override
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/storage/presentation/StorageController.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/storage/presentation/StorageController.java
index 4be862e6..0b0454b1 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/storage/presentation/StorageController.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/storage/presentation/StorageController.java
@@ -8,6 +8,7 @@
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
+import javax.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort.Direction;
@@ -44,7 +45,7 @@ public void saveNotificationToStorage(@PathVariable("notification_id") Long noti
     @Operation(summary = "보관함에 저장한 푸쉬알림 삭제")
     @ResponseStatus(HttpStatus.OK)
     @DeleteMapping
-    public void deleteNotificationFromStorage(@RequestBody DeleteStorage request) {
+    public void deleteNotificationFromStorage(@Valid @RequestBody DeleteStorage request) {
         storageService.deleteNotificationFromStorage(request);
     }
 }
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/domain/storage/presentation/dto/request/DeleteStorage.java b/src/main/java/io/github/depromeet/knockknockbackend/domain/storage/presentation/dto/request/DeleteStorage.java
index 2224951b..73a5bc5a 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/domain/storage/presentation/dto/request/DeleteStorage.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/domain/storage/presentation/dto/request/DeleteStorage.java
@@ -2,9 +2,13 @@
 
 
 import java.util.List;
+import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Size;
 import lombok.Getter;
 
 @Getter
 public class DeleteStorage {
+    @Size(min = 1)
+    @NotNull
     List<Long> storageIds;
 }
diff --git a/src/main/java/io/github/depromeet/knockknockbackend/global/error/ExceptionFilter.java b/src/main/java/io/github/depromeet/knockknockbackend/global/error/ExceptionFilter.java
index ed6e56ab..2622fcfa 100644
--- a/src/main/java/io/github/depromeet/knockknockbackend/global/error/ExceptionFilter.java
+++ b/src/main/java/io/github/depromeet/knockknockbackend/global/error/ExceptionFilter.java
@@ -6,7 +6,6 @@
 import io.github.depromeet.knockknockbackend.global.error.exception.KnockException;
 import java.io.IOException;
 import javax.servlet.FilterChain;
-import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import lombok.RequiredArgsConstructor;
@@ -21,35 +20,36 @@ public class ExceptionFilter extends OncePerRequestFilter {
     @Override
     protected void doFilterInternal(
             HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
-            throws ServletException, IOException {
+            throws IOException {
         try {
             filterChain.doFilter(request, response);
         } catch (KnockException e) {
-            response.getWriter()
-                    .write(
-                            objectMapper.writeValueAsString(
-                                    getErrorResponse(
-                                            e.getErrorCode(), request.getRequestURL().toString())));
+            writeErrorResponse(response, e.getErrorCode(), request.getRequestURL().toString());
         } catch (Exception e) {
             if (e.getCause() instanceof KnockException) {
-                response.getWriter()
-                        .write(
-                                objectMapper.writeValueAsString(
-                                        getErrorResponse(
-                                                ((KnockException) e.getCause()).getErrorCode(),
-                                                request.getRequestURL().toString())));
+                writeErrorResponse(
+                        response,
+                        ((KnockException) e.getCause()).getErrorCode(),
+                        request.getRequestURL().toString());
             } else {
                 e.printStackTrace();
-                getErrorResponse(
-                        ErrorCode.INTERNAL_SERVER_ERROR, request.getRequestURL().toString());
+                writeErrorResponse(
+                        response,
+                        ErrorCode.INTERNAL_SERVER_ERROR,
+                        request.getRequestURL().toString());
             }
-        } finally {
-            response.setContentType(MediaType.APPLICATION_JSON_VALUE);
         }
     }
 
-    private ErrorResponse getErrorResponse(ErrorCode errorCode, String path) {
-        return new ErrorResponse(
-                errorCode.getStatus(), errorCode.getCode(), errorCode.getReason(), path);
+    private void writeErrorResponse(HttpServletResponse response, ErrorCode errorCode, String path)
+            throws IOException {
+        ErrorResponse errorResponse =
+                new ErrorResponse(
+                        errorCode.getStatus(), errorCode.getCode(), errorCode.getReason(), path);
+
+        response.setStatus(errorCode.getStatus());
+        response.setCharacterEncoding("UTF-8");
+        response.setContentType(MediaType.APPLICATION_JSON_VALUE);
+        response.getWriter().write(objectMapper.writeValueAsString(errorResponse));
     }
 }