To provide a lock-confirmation supporting device which helps a user to do the lock confirmation with the senses of a
human being easily and surely at the time right after the locking operation, and to do the lock reconfirmation easily after being locked. A lock-confirmation supporting device is constituted of a
key holder portion (2) in which a key is held and out of which it is taken by a user for locking and an electronic
clock portion (3) comprising a
clock circuit, CPU, ROM, RAM and a display unit. The lock-confirmation supporting device generates a lock-confirmed
signal upon the user'
s key-returned action right after the locking oepration. Upon the lock-confirmed
signal, the lock-confirming device stores in the RAM of the electronic
clock portion (3) the real time as the lock-confirmed time and informs the user of the lock-confirmed time by displaying it on a
liquid crystal display unit (18). The lock-confirmed
signal is generated by a key-taken out or key-returned sensor means, a locking sound detecting means including locking sound sensor, for example, a
microphone (5a) and the like or manual input switch (22) provided in the
key holder portion (2). The lock-confirmed time stored in the RAM is displayed on the
liquid crystal display unit (18) by operating a reconfirmation switch (7) after locking.