diff --git a/Diary/Controller/CreateDiaryViewController.swift b/Diary/Controller/CreateDiaryViewController.swift
index 9a752d6f2..98320985e 100644
--- a/Diary/Controller/CreateDiaryViewController.swift
+++ b/Diary/Controller/CreateDiaryViewController.swift
@@ -15,10 +15,10 @@ final class CreateDiaryViewController: UIViewController, AlertDisplayable, Share
         
         return textView
     }()
-
+    
     private let container = CoreDataManager.shared.persistentContainer
-    var diary: Diary
-    var isNew: Bool
+    private var diary: Diary
+    private var isNew: Bool
     
     init() {
         self.diary = CoreDataManager.shared.createDiary()
@@ -43,7 +43,7 @@ final class CreateDiaryViewController: UIViewController, AlertDisplayable, Share
         setupNavigationBarButton()
         setupNotification()
     }
-
+    
     private func configureUI() {
         view.backgroundColor = .systemBackground
         self.title = DateFormatter().formatToString(from: Date(), with: "YYYY년 MM월 dd일")
@@ -75,7 +75,7 @@ final class CreateDiaryViewController: UIViewController, AlertDisplayable, Share
         let moreButton = UIBarButtonItem(title: "더보기", style: .plain, target: self, action: #selector(showMoreOptions))
         navigationItem.rightBarButtonItem = moreButton
     }
-
+    
     private func setupNotification() {
         NotificationCenter.default.addObserver(self,
                                                selector: #selector(keyboardWillShow),
@@ -94,13 +94,13 @@ final class CreateDiaryViewController: UIViewController, AlertDisplayable, Share
         let cancelAction = UIAlertAction(title: "취소", style: .cancel)
         let deleteAction = UIAlertAction(title: "삭제", style: .destructive) { [weak self] _ in
             guard let self else { return }
-            CoreDataManager.shared.deleteDiary(diary)
+            CoreDataManager.shared.deleteDiary(self.diary)
             self.navigationController?.popViewController(animated: true)
         }
         
         showAlert(title: "진짜요?", message: "정말로 삭제하시겠어요?", actions: [cancelAction, deleteAction])
     }
-
+    
     deinit {
         NotificationCenter.default.removeObserver(self)
     }
diff --git a/Diary/Controller/DiaryListViewController.swift b/Diary/Controller/DiaryListViewController.swift
index b4b46acf4..06b77cd82 100644
--- a/Diary/Controller/DiaryListViewController.swift
+++ b/Diary/Controller/DiaryListViewController.swift
@@ -6,7 +6,7 @@
 
 import UIKit
 
-final class DiaryListViewController: UIViewController, AlertDisplayable, ShareDiary {
+final class DiaryListViewController: UIViewController {
     private let tableView: UITableView = {
         let tableView = UITableView()
         tableView.translatesAutoresizingMaskIntoConstraints = false
@@ -20,7 +20,7 @@ final class DiaryListViewController: UIViewController, AlertDisplayable, ShareDi
     
     override func viewDidLoad() {
         super.viewDidLoad()
-
+        
         configureUI()
         setupNavigationBarButton()
         setupTableView()
@@ -61,7 +61,9 @@ final class DiaryListViewController: UIViewController, AlertDisplayable, ShareDi
         tableView.delegate = self
         tableView.register(DiaryListTableViewCell.self, forCellReuseIdentifier: DiaryListTableViewCell.identifier)
     }
-    
+}
+
+extension DiaryListViewController: AlertDisplayable {
     private func readCoreData() {
         do {
             let fetchedDiaries = try container.viewContext.fetch(Diary.fetchRequest())
@@ -74,7 +76,7 @@ final class DiaryListViewController: UIViewController, AlertDisplayable, ShareDi
     }
 }
 
-extension DiaryListViewController: UITableViewDataSource, UITableViewDelegate {
+extension DiaryListViewController: UITableViewDataSource {
     func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
         diaryList.count
     }
@@ -94,12 +96,14 @@ extension DiaryListViewController: UITableViewDataSource, UITableViewDelegate {
         
         return cell
     }
-    
+}
+
+extension DiaryListViewController: UITableViewDelegate, ShareDiary {
     func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
         tableView.deselectRow(at: indexPath, animated: true)
         let diaryToEdit = diaryList[indexPath.row]
         let createVC = CreateDiaryViewController(diaryToEdit)
-
+        
         navigationController?.pushViewController(createVC, animated: true)
     }