PURPOSE: To attain a repeated attempt without returning a coin to the repeated attempt due to mis-dialing, by detecting a ring-forward signal from a coin telephone.

CONSTITUTION: In the coin telephone 1 where a ring-forward signal transmitter 4 is provided, when the transmitter 4 is operated after mis-dialing or the end of call with a generic subscriber 3 after calling once, this signal is received at the ring-forward signal receiver 5 connected to the telephone set 1 after calling. A central controller 6 connects a dial tone signal transmitter 7 to the telephone set 1, transmits a dial tone and receives the dial signal with a dial signal receiver 8, allowing to connect the telephone set in conventional ways.