To control a long distance call.

When a terminating call portable telephone which calls from a caller telephone and an exchange in which there is the terminating call telephone can be detected (step S4), interexchange distance between an exchange in which there is the caller telephone and the exchange in which there is the terminating call portable telephone is obtained (step S5), if the interexchange distance is shorter than a specified distance predetermined, the caller telephone and the terminating call portable telephone are connected (step S9) and, if the interexchange distance is longer than the specified distance, a guidance is returned for indicating to the caller telephone that the terminating call portable telephone is distant more than the specified distance (step S8).