diff --git a/src/main/java/in/koreatech/koin/domain/community/lostitem/chatroom/controller/LostItemChatRoomApi.java b/src/main/java/in/koreatech/koin/domain/community/lostitem/chatroom/controller/LostItemChatRoomApi.java
index 563e33bd4..dcb1ef4ac 100644
--- a/src/main/java/in/koreatech/koin/domain/community/lostitem/chatroom/controller/LostItemChatRoomApi.java
+++ b/src/main/java/in/koreatech/koin/domain/community/lostitem/chatroom/controller/LostItemChatRoomApi.java
@@ -61,6 +61,17 @@ public interface LostItemChatRoomApi {
                     """)
             })
         ),
+        @ApiResponse(responseCode = "404", description = "리소스 없음",
+            content = @Content(mediaType = "application/json", examples = {
+                @ExampleObject(name = "채팅 상대방 탈퇴", summary = "채팅 상대방이 존재하지 않습니다.", value = """
+                    {
+                      "message": "채팅 상대방이 존재하지 않습니다.",
+                      "errorTraceId": "123e4567-e89b-12d3-a456-426614174000",
+                      "code": "NOT_FOUND_CHAT_PARTNER"
+                    }
+                    """)
+            })
+        )
     })
     @Operation(
         summary = "분실물 게시글에서 직접 채팅방 진입시 채팅방 데이터 생성, 필요한 데이터 반환",
@@ -110,6 +121,13 @@ ResponseEntity<ChatRoomInfoResponse> createLostItemChatRoom(
                       "errorTraceId": "123e4567-e89b-12d3-a456-426614174000",
                       "code": "NOT_FOUND_LOST_ITEM_CHATROOM"
                     }
+                    """),
+                @ExampleObject(name = "채팅 상대방 탈퇴", summary = "채팅 상대방이 존재하지 않습니다.", value = """
+                    {
+                      "message": "채팅 상대방이 존재하지 않습니다.",
+                      "errorTraceId": "123e4567-e89b-12d3-a456-426614174000",
+                      "code": "NOT_FOUND_CHAT_PARTNER"
+                    }
                     """)
             })
         ),
diff --git a/src/main/java/in/koreatech/koin/domain/community/lostitem/chatroom/service/LostItemArticleInfoService.java b/src/main/java/in/koreatech/koin/domain/community/lostitem/chatroom/service/LostItemArticleInfoService.java
index d59cdd3bd..2a6c8f440 100644
--- a/src/main/java/in/koreatech/koin/domain/community/lostitem/chatroom/service/LostItemArticleInfoService.java
+++ b/src/main/java/in/koreatech/koin/domain/community/lostitem/chatroom/service/LostItemArticleInfoService.java
@@ -1,7 +1,10 @@
 package in.koreatech.koin.domain.community.lostitem.chatroom.service;
 
+import java.util.Optional;
+
 import org.springframework.stereotype.Service;
 
+import in.koreatech.koin.domain.user.model.User;
 import in.koreatech.koin.global.code.ApiResponseCode;
 import in.koreatech.koin.global.exception.CustomException;
 import in.koreatech.koin.domain.community.article.model.Article;
@@ -31,6 +34,8 @@ public String getChatPartnerProfileImage(Integer articleId) {
             () -> CustomException.of(ApiResponseCode.NOT_FOUND_ARTICLE)
         );
 
-        return lostItemArticle.getAuthor().getProfileImageUrl();
+        User author = Optional.ofNullable(lostItemArticle.getAuthor())
+            .orElseThrow(() -> CustomException.of(ApiResponseCode.NOT_FOUND_CHAT_PARTNER));
+        return author.getProfileImageUrl();
     }
 }
diff --git a/src/main/java/in/koreatech/koin/global/code/ApiResponseCode.java b/src/main/java/in/koreatech/koin/global/code/ApiResponseCode.java
index 207dc2476..f0dc8cc43 100644
--- a/src/main/java/in/koreatech/koin/global/code/ApiResponseCode.java
+++ b/src/main/java/in/koreatech/koin/global/code/ApiResponseCode.java
@@ -130,6 +130,7 @@ public enum ApiResponseCode {
     NOT_FOUND_SHOP(HttpStatus.NOT_FOUND, "상점이 존재하지 않습니다."),
     NOT_FOUND_COOP_SEMESTER(HttpStatus.NOT_FOUND, "해당 학기가 존재하지 않습니다."),
     NOT_FOUND_SHOP_ORDER_SERVICE_REQUEST(HttpStatus.NOT_FOUND, "상점 서비스 전환 요청이 존재하지 않습니다."),
+    NOT_FOUND_CHAT_PARTNER(HttpStatus.NOT_FOUND, "채팅 상대방이 존재하지 않습니다."),
 
     /**
      * 409 CONFLICT (중복 혹은 충돌)