diff --git a/backend/src/main/java/codesquard/app/api/item/ItemService.java b/backend/src/main/java/codesquard/app/api/item/ItemService.java
index da98eaf6c..61e719220 100644
--- a/backend/src/main/java/codesquard/app/api/item/ItemService.java
+++ b/backend/src/main/java/codesquard/app/api/item/ItemService.java
@@ -108,11 +108,11 @@ public ItemDetailResponse findDetailItemBy(Long itemId, Principal principal) {
 		boolean isInWishList = wishRepository.existsByMemberIdAndItemId(principal.getMemberId(), itemId);
 
 		if (item.isSeller(principal.getMemberId())) {
-			Long chatRoomId = chatRoomRepository.findByItemIdAndMemberId(itemId, principal.getMemberId())
-				.orElse(null);
-			return ItemDetailResponse.toSeller(item, principal.getMemberId(), imageUrls, isInWishList, chatRoomId);
+			return ItemDetailResponse.toSeller(item, principal.getMemberId(), imageUrls, isInWishList);
 		}
-		return ItemDetailResponse.toBuyer(item, principal.getMemberId(), imageUrls, isInWishList);
+		Long chatRoomId = chatRoomRepository.findByItemIdAndMemberId(itemId, principal.getMemberId())
+			.orElse(null);
+		return ItemDetailResponse.toBuyer(item, principal.getMemberId(), imageUrls, isInWishList, chatRoomId);
 	}
 
 	@Transactional
diff --git a/backend/src/main/java/codesquard/app/api/item/response/ItemDetailResponse.java b/backend/src/main/java/codesquard/app/api/item/response/ItemDetailResponse.java
index 11853af29..c5a1a0979 100644
--- a/backend/src/main/java/codesquard/app/api/item/response/ItemDetailResponse.java
+++ b/backend/src/main/java/codesquard/app/api/item/response/ItemDetailResponse.java
@@ -51,7 +51,7 @@ private ItemDetailResponse(boolean isSeller, List<String> imageUrls, String sell
 	}
 
 	public static ItemDetailResponse toBuyer(Item item, Long loginMemberId, List<String> imageUrls,
-		boolean isInWishList) {
+		boolean isInWishList, Long chatRoomId) {
 		Member seller = item.getMember();
 		boolean isSeller = seller.equalId(loginMemberId);
 		return ItemDetailResponse.builder()
@@ -68,11 +68,12 @@ public static ItemDetailResponse toBuyer(Item item, Long loginMemberId, List<Str
 			.viewCount(item.getViewCount())
 			.price(item.getPrice())
 			.isInWishList(isInWishList)
+			.chatRoomId(chatRoomId)
 			.build();
 	}
 
 	public static ItemDetailResponse toSeller(Item item, Long loginMemberId, List<String> imageUrls,
-		boolean isInWishList, Long chatRoomId) {
+		boolean isInWishList) {
 		Member seller = item.getMember();
 		boolean isSeller = seller.equalId(loginMemberId);
 		return ItemDetailResponse.builder()
@@ -89,7 +90,6 @@ public static ItemDetailResponse toSeller(Item item, Long loginMemberId, List<St
 			.viewCount(item.getViewCount())
 			.price(item.getPrice())
 			.isInWishList(isInWishList)
-			.chatRoomId(chatRoomId)
 			.build();
 	}
 
diff --git a/backend/src/test/java/codesquard/app/api/item/ItemControllerTest.java b/backend/src/test/java/codesquard/app/api/item/ItemControllerTest.java
index 3b6297599..3dcd9eb0f 100644
--- a/backend/src/test/java/codesquard/app/api/item/ItemControllerTest.java
+++ b/backend/src/test/java/codesquard/app/api/item/ItemControllerTest.java
@@ -69,8 +69,9 @@ public void findDetailItemBySeller() throws Exception {
 			"가락동", "thumbnailUrl", seller, sport);
 		List<String> imageUrls = List.of("imageUrlValue1", "imageUrlValue2");
 
-		ItemDetailResponse response = ItemDetailResponse.toBuyer(item, seller.getId(), imageUrls, false);
+		ItemDetailResponse response = ItemDetailResponse.toBuyer(item, seller.getId(), imageUrls, false, null);
 		given(itemService.findDetailItemBy(any(), any())).willReturn(response);
+		
 		// when & then
 		mockMvc.perform(get("/api/items/1"))
 			.andExpect(status().isOk())
@@ -102,7 +103,7 @@ public void findDetailItemByBuyer() throws Exception {
 		Long loginMemberId = 9999L;
 		List<String> imageUrls = List.of("imageUrlValue1", "imageUrlValue2");
 
-		ItemDetailResponse response = ItemDetailResponse.toSeller(item, loginMemberId, imageUrls, false, 1L);
+		ItemDetailResponse response = ItemDetailResponse.toSeller(item, loginMemberId, imageUrls, false);
 		given(itemService.findDetailItemBy(any(), any())).willReturn(response);
 		// when & then
 		mockMvc.perform(get("/api/items/1"))