diff --git a/dislocker.py b/dislocker.py
index 991fbb0..7adde0d 100644
--- a/dislocker.py
+++ b/dislocker.py
@@ -60,6 +60,28 @@ class Bot(discord.Client):
                         cursor.execute("UPDATE pc_list SET password_hash = %s WHERE pc_number = %s", (password_hash, pc_number))
                         self.db.commit()
                         result = {"result": "ok", "password": str(password), "name": str(user_record[0][1])}
+            else:
+                cursor.execute("SELECT * FROM pc_usage_history WHERE member_id=%s ORDER BY id DESC LIMIT 1", (user_record[0][0],))
+                pc_usage_history_record = cursor.fetchall()
+                if pc_usage_history_record:
+                    if pc_usage_history_record[0][5] == None:
+                        result = {"result": "pc_already_in_use_by_you", "pc_number": str(pc_usage_history_record[0][2]), "device_number": str(pc_usage_history_record[0][3]), "start_time": str(pc_usage_history_record[0][4]), "detail": str(pc_usage_history_record[0][6])}
+                    else:
+                        cursor.execute("SELECT * FROM pc_list WHERE pc_number=%s", (pc_number,))
+                        pc_list_record = cursor.fetchall()
+                        if not pc_list_record[0][1] == None:
+                            result = {"result": "pc_already_in_use_by_other"}
+                        else:
+                            if detail == None:
+                                cursor.execute("INSERT INTO pc_usage_history (member_id, pc_number, device_number, start_use_time) VALUES (%s, %s, %s, current_timestamp)", (user_record[0][0], pc_number, device_number))
+                            #使用用途があるとき
+                            else:
+                                cursor.execute("INSERT INTO pc_usage_history (member_id, pc_number, device_number, start_use_time, use_detail) VALUES (%s, %s, %s, current_timestamp, %s)", (user_record[0][0], pc_number, device_number, detail))
+                            
+                            cursor.execute("UPDATE pc_list SET using_user_id = %s WHERE pc_number = %s", (user_record[0][0], pc_number))
+                            cursor.execute("UPDATE pc_list SET password_hash = %s WHERE pc_number = %s", (password_hash, pc_number))
+                            self.db.commit()
+                            result = {"result": "ok", "password": str(password), "name": str(user_record[0][1])}
 
         return result