PURPOSE: To display the value of a card effectively to a card user by controlling a display device so that the money value of the card is displayed when the card is inserted and returned and the remaining time is displayed during the output period of a control signal.

CONSTITUTION: When the card is inserted, the control signal is outputted according to the money value recorded on the card and the amount of money corresponding to the output time of the control signal is subtracted from the money value that the card has to calculate the remaining money value. Then an equipment 20 which is connected to the card timer receives the control signal and operates. At this time, the display device 6 is controlled by a display controller 10 to display the money value when the card is inserted and returned and the remaining time during the output period of the control signal. Consequently, the remaining amount of money and the remaining time are switched and displayed and the value of the card is displayed effectively to the card user.