PURPOSE: To erase even a registered code number only by jointly using easy key operation of a sign input means when a manager of a locker or the like forcedly unlocks a door by a master key.

CONSTITUTION: A battery type electronic lock device is composed of a sign input part 1, a control circuit part 2 such as a computer having a sign reading means 2a, a digit counting means 2b, a timer means 2c, a temporary storage means 2g, a registering storage means 2h, a locking unlocking signal generating means 2j, a comparing judging means 2m and a sign erasing means 2n and a lock mechanism part 3 having a lock actuating part 3b, a lock condition detecting part 3c and a door or the like condition detecting part 3d. In the case where a manager forcedly unlocks the lock actuating part 3b by a master key 3a for cleaning or the like, when key operation of the sign input part 1 is jointly used, the sign erasing means 2n which receives sign input from the sign reading means 2a and a forced unlocking signal 2r from the comparing judging means 2m receiving a forced unlocking detecting signal 3g from the lock condition detecting part 3c, outputs a registered sign erasing signal 2s, and erases even a registered code number of the registering storage means 2h.