PURPOSE: To realize a coin telephone set which is capable of utilizing the amount of coins thrown in by a user, by making an arrangement that, the user sends a recall signal at the time of completion of a call and the exchange side receives the recall signal, stops the imposition pulse, and releases the talking line.

CONSTITUTION: When a user completes a call with a coin telephone set 10 and wants to make another call to another subscriber, the user dials the telephone number of the subscriber as a recall signal (r) under the off-hook condition. Then the recall signal (r) is received by the recall signal receiving circuit 33 of a control trunk (CRT) 16 of a coin telephone set and is transferred to a central controller (CC) 11. Upon receiving the signal (r), the CC 11 delivers an indication for stopping the transmission of an imposition pulse signal (c) to an imposition pulse sending out circuit 32. Furthermore, the CC 11 releases the out going line trunk 15 which has been used for the talk of the user and delivers a dial tone to the coin telephone set again, and then, connects an originating register for receiving the dial number.