To emit intermittent warning, capable at first of imparting sense of unease and of danger to a person trying to infiltrate a house, when unlocking operation by picking is performed and then imparting fright feeding to make him expelled immediately.

This picking warning device, capable of emitting a warning by detecting the vibration due to the unlocking operation by the picking, comprises a sensor part 11 for detecting the vibration due to the unlocking operation. When the sensor part 11 detects the vibration due to the unlocking operation through the picking, a warning output control part A allows a warning device 18 to output a pre-warning and a main warning specified time after the pre-warning.