PURPOSE: To execute an incoming rejection having a convenience property by providing an incoming rejecting information memory for storing an incoming flag, an incoming allowing calling party class and a calling party number.

CONSTITUTION: When a calling extension A dials a called party number B, an incoming rejecting information memory 21 is retrieved. By the called party number B, an incoming rejecting flag is checked, and when it is '1', an incoming calling party class and a class of the calling extension A are compared. When they do not coincide, an incoming allowing calling party number and a number of the calling extension A are compared. When they do not coincide either, a connection control sound trunk ROT 4 is connected to the calling extension A, and a connection control sound is sent out. On the other hand, when the incoming rejecting flag is '0', or the calling party class or number has coincided, the connection is executed.