PURPOSE: To make entry into a room expedient by providing a receiver, an alarm device, etc., to a control signal generating means, and also juxtaposing a feeble type transmitter that always transmits identification information as a key, and enabling a user to unlock doing nothing but approaching to it.

CONSTITUTION: A receiver 4 provided with a directional antenna, an alarm device 12, etc., are provided to a control signal generating means 8 that controls open/close of an electric lock 9. On the other hand, a feeble electricity type transmitter 1 that always transmits identification information stored in a memory is juxtaposed as a key. And, if a user does not carry the key (transmitter 1) with him when he walks out of a room, the alarming device such as a buzzar, etc., works, and, at the same time, he unlocks doing nothing but approaching with the key when he enters into the room. Also, inputting of a secret number may be performed at need, permitting the user to enter into the room with ease even when he is loaded with baggage.