PURPOSE: To prepay currency substitutes and to discriminate these substitutes after the use by discriminating currency substitutes in a parking device allowing the use of them.

CONSTITUTION: Currency substitutes or these substitutes and currency are thrown in for the charge for parking calculated by a parking charge calculation means 5 of a parking control part 1. When currency substitutes are thrown in, classifications of currency substitutes and the number of currency substitutes of each classification are measured by a currency substitute measuring part 2 to calculate the amount of money of thrown-in currency substitutes, and it is subtracted from the charge for parking calculated by the parking control part 1; and when the subtraction result is 0, a lock mechanism 8 is operated to permit a vehicle to leave. If the amount of money of thrown-in currency substitutes is smaller than the charge for parking, currency may be thrown in. The amount of money of thrown-in currency is calculated by a currency demand control part 4; and when the sum total of the amount of money of thrown-in currency substitutes and that of thrown-in currency is equal to the charge for parking, the mechanism 8 is released. Data of thrown-in currency substitutes is post-processed in a currency substitute classifying part 3 to specify a currency substitute issuer and to demand the money for used currency substitutes.