PURPOSE: To anser easily a call when an operator is absent by registering a reception call signal as an incoming call number and performing a prescribed incoming call operation based on the registered number.

CONSTITUTION: A collation circuit 3 decides the propriety for answering in accordance with the call number received by a reception circuit 1. Then a driver circuit 8 and a display device 9 decide that the answering is possible. When an operator is absent, the number stored in a calling side number memory 4 is transferred and stored to a called side number memory 6. Then the called side number is displayed at the device 9 with a blinking. When the operator comes back and peforms a prescribed incoming operation to a calling operation switch 15 based on the blinking display, the calling is carried out in response to the number stored in the memory 6. In such a way, it is easy to answer the call received when the operator is absent.