To clean dirt of a card carrying belt without visit of a maintenance personnel to a location where a telephone set is installed by providing a polish belt and a solenoid to make the polish belt contact onto the card carrying belt.

When a counter 6 counts a telephone card detection signal outputted from a card sensor by a prescribed number of times, the counter 6 provides an output of a count-up signal. A motor solenoid drive circuit 7 receives this signal to output a drive signal to a solenoid 9 and a motor 10. The solenoid 9 is driven, a solenoid shaft 91 is descended, and a roller 12 is descended via a spring 14. A polish belt 8 is descended and in contact with a card carrier belt 3. The polish belt 8 is wound on a winding roller 11 by the drive of the motor 10 and moved little by little. When the solenoid 9 and the motor 10 are operated for a prescribed time, they are deenergized by a signal from the drive circuit 7.