To provide a lock having a device consisting of a pair of an inner lock main body unit and an indoor electric unit, and has a mechanism for turning on an electric light simultaneously when the lock is unlocked, and setting to make an emergency sound when a key not mated with the lock is used.

The code (2) indicates that the device linked to an indoor electric light is attached to a lock main body. The code (3) is a device for turning on/off the emergency sound when an outer key not mated with the lock is used. The code (4) is an indoor electric device, and is provided with a device linked to a door main body lock unit. The device (4) turns on the indoor electric lights simultaneously when the lock main body (2) is unlocked.