PURPOSE: To provide a switching function at low cost by providing an automatic connection control part for controlling an originating call by reading information from an address storage part in the case of originating a call from a terminal and connecting the call.

CONSTITUTION: When any call comes in on the side of a terminal 1, a communication control part 5 fetches the call originating terminal address of this incoming call from the incoming call signal and reports the information to an address storage part 6. The address storage part 6 stores and manages the information. Then, an auxiliary system host computer 4 originates/disconnects the call to the terminal so as to store the address of the auxiliary system host computer 4 in the address storage part 6. Next, when a work application 7 requires host connection, the job application 7 instructs the host connection to an automatic connection control part 8, and the automatic connection control part 8 possesses the address of the host computer stored in the address storage part 6 from this address storage part 6.