PURPOSE: To make a gateway door not lockable on occasion of going out unless items for preserving interior security are confirmed by providing electric contacts and a clutch-gear type mechanism.

CONSTITUTION: A grip part 1 of a key holder main body and a key-holding part 2 are connected with a clutch mechanism composed of a rotary shaft 3, a rotor 4, a core shaft 7 and a spring 8. A solenoid 12 serving as a motive power for driving the clutch mechanism is driven by operations of a plurality of electric contacts 15 arranged in series and a main switch 14, and thereby the clutch mechanism is driven and turning effect for turning the grip part 1 of the key holder main body is transmitted to the key-holding part 2. The movement of the rotor 4 is controlled by a cam part 5, a latch shaft 11 and a spring 9, and the states of locking and unlocking are differentially indicated by an indicator part 6.