PURPOSE: To easily cope with the change of a payment method in a short period of time by deciding the payment method of higher priority in preference to the payment of lower priority regardless of a method of payment and an input order of amount of money.

CONSTITUTION: A RAM 3 includes a sale total memory, a priority counter, etc. When the payment method and the deposit amount that are designated by a customer are inputted, the difference is calculated between the total amount of money stored in the sale total memory and the total deposit amount of various payment methods. If the difference is equal to the positive value, the difference is displayed as a payment balance at a display part consisting of a front side display unit 11 and a customer side display unit 12. If the difference is equal to 0 or less, the deposit amount of the corresponding payment method is compared with the difference in the order of lower priority that is set by a priority setting means. Thus the repayment data can be acquired. Then the repayment data is shown at the display part and also a settlement flag is set.