To prevent a person from going out without notice to the outside of a house or a home by detecting him by a detector when he approaches a door and locking the door by a driving device.

In a driving device A, when a pinion 4 is normally rotated by the reversible motion of a motor 5, a protrusible locking piece 2 is protruded to lock a door and when the pinion is reversely rotated, the locking piece 2 is retracted to unlock the door. A detector for persons connected to drive the driving device A is installed in the vicinity of the door 1 in the indoor side of a house or a home. A projector and a receiver are oppositely arranged at both sides of the door 1 inside for instance in the detector. When a person passes between the projector and the receiver, as the light from the projector can not be received in the receiver, the person is detected. In this time, the motor 5 of the driving device A connected to the detector is normally rotated to lock the door and hence, the device prevents a wandering person from going out of a house or a home without notice.