PURPOSE: To provide safe and reliable communications with the parties concerned about the fact that an operator is being threatened to operate security ten keys, without using an emergency number and being unnoticed by an intimidator.

CONSTITUTION: If an operator enters his own code numbers, using key switches 10-19 just like he is under normal conditions, and presses a key switch 21 with a pressing force larger than a specified value, contact points a1 and a2, b1 and b2 respectively close and contact. Like under a normal condition, an OK signal and an input code from a collating circuit 3 are sent out to a monitor computer 7 via a data transmission circuit 6, and unlocks a door, however, contact points b1 and b2 of the key switch 21 contact and close each other and, consequently, an emergency signal is sent out to the monitor computer 7 via the data transmission circuit 6. If someone else erroneously presses the key switch ENT 21 too hard, a collation result becomes NG, an emergency signal together with an NG signal are sent out and an unlocking signal is not sent out and the door remains closed.