PURPOSE: To connect an incoming call to a designated terminal by applying a single subscriber number and a subscriber class showing the group constitution of plural terminals to a subscriber unit provided with plural terminals and dialing a selection code designating each terminal inside the group.

CONSTITUTION: When a caller, who originates a call from a CLG 1 and hears a dial tone from an SPCA 2, dials a subscriber number N, at the SPCA 2, it is recognized from the subscriber class of the subscriber number N that a subscriber to be called owns plural terminals, and the input of the selection code of a terminal to be called is pressed. When the selection code of the terminal to be called is received from the CLG 1, at the SPCA 2, the terminal number of the designated terminal to be called is extracted from a terminal number list n21, which is provided by retrieving a terminal number translation list 20 with the subscriber number N, corresponding to the selection code. When the terminal to be called of this terminal number is accommodated in the present station, a central processing unit performs the in-present station connection processing of the CLG 1 to a CLD 41 or CLD 42 and when it is accommodated in the other station, the call is terminated to a CLD 51 by performing outgoing connection processing to a repeater line 6.