diff --git a/src/main/java/com/ceos/bankids/domain/Challenge.java b/src/main/java/com/ceos/bankids/domain/Challenge.java
index 65a1615..6b52cb6 100644
--- a/src/main/java/com/ceos/bankids/domain/Challenge.java
+++ b/src/main/java/com/ceos/bankids/domain/Challenge.java
@@ -82,7 +82,7 @@ public class Challenge extends AbstractTimestamp {
 
     @Column()
     @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd hh:mm:ss", timezone = "Asia/Seoul")
-    private Timestamp deleted_at;
+    private Timestamp deletedAt;
 
     @ManyToOne(fetch = FetchType.LAZY)
     @JoinColumn(name = "targetItemId", nullable = false)
diff --git a/src/main/java/com/ceos/bankids/repository/ChallengeRepository.java b/src/main/java/com/ceos/bankids/repository/ChallengeRepository.java
index cc5db90..5921c1a 100644
--- a/src/main/java/com/ceos/bankids/repository/ChallengeRepository.java
+++ b/src/main/java/com/ceos/bankids/repository/ChallengeRepository.java
@@ -11,8 +11,8 @@ public interface ChallengeRepository extends JpaRepository<Challenge, Long> {
 
     public List<Challenge> findByContractUserId(Long contractUserId);
 
-    public List<Challenge> findAllByDeleted_atIsNotNullOrderByIdDesc();
+    public List<Challenge> findAllByDeletedAtIsNotNullOrderByIdDesc();
 
-    public List<Challenge> findByChallengeStatusAndDeleted_atIsNotNullOrderByIdDesc(
+    public List<Challenge> findByChallengeStatusAndDeletedAtIsNotNullOrderByIdDesc(
         String challengeStatus);
 }
diff --git a/src/main/java/com/ceos/bankids/service/ChallengeServiceImpl.java b/src/main/java/com/ceos/bankids/service/ChallengeServiceImpl.java
index b5a7893..cfd923b 100644
--- a/src/main/java/com/ceos/bankids/service/ChallengeServiceImpl.java
+++ b/src/main/java/com/ceos/bankids/service/ChallengeServiceImpl.java
@@ -386,8 +386,8 @@ public ChallengeCompleteDeleteByKidMapperDTO challengeCompleteDeleteByKid(
     public List<ChallengeDTO> readChallengeHistory(String status) {
 
         List<Challenge> challengeHistoryList =
-            status == null ? challengeRepository.findAllByDeleted_atIsNotNullOrderByIdDesc()
-                : challengeRepository.findByChallengeStatusAndDeleted_atIsNotNullOrderByIdDesc(
+            status == null ? challengeRepository.findAllByDeletedAtIsNotNullOrderByIdDesc()
+                : challengeRepository.findByChallengeStatusAndDeletedAtIsNotNullOrderByIdDesc(
                     status);
         return challengeHistoryList.stream().map(challenge -> {
             if (challenge.getChallengeStatus() == ChallengeStatus.ACHIEVED