PURPOSE: To realize efficient dialing/incoming call by changing the method for incoming call display in accordance with the contents of the incoming call to reduce an wastefull incoming call.

CONSTITUTION: A call control signal sent from an ISDN line 101 is analyzed by an ISDN protocol control means 102 and information of a layer 3 protocol is inputted to a call control means 103 as protocol primitive. The call control means 103 analyzes protocol primitive and after confirming the incoming call is an own terminal, the means 103 analyzes information transfer ability within the transfer ability information element of the layer 3 protocol. Furthermore, in accordance with the analyzed information transfer ability, for example, in accordance with the contents for which the information transfer ability is 'sound', 'nonrestrictive digital' or the like, different kinds of incoming call informing signals are generated. An incoming call generating means 104 switches a switch 105 in accordance with the incoming call informing signal so that an incoming call signal is inputted to an incoming call display part 106 or a ringer sound generation circuit 108.