PURPOSE: To judge whether communication with the other communicating party terminal is enabled in an individual mode or not by using a high-order later matching information element in a call setting message and a low-order layer matching information element in a response message at the time of connecting a call.

CONSTITUTION: Information inputted from a key operation 5 by a call transmitting side user for transmission of the call is reported through a terminal control part 9 to a call control processing part 12. The call control processing part 12 prepares the call setting message containing the high-order layer matching information element which a communication judge part 15 prepares for inserting an individual code for identifying a system and transmits the message to an ISDN. When it is judged that the communication with the other communicating party terminal by the individual mode is enabled, a call incoming side user receiving the message transmits the response message while containing the individual code in the low-order layer matching information element. The call transmitting side user receiving the response message detects the individual code in the low-order layer matching information element and can confirm the communication with the call incoming side terminal is enabled in the individual mode.