A fully automated system for the work of fee payment in supermarkets and other distribution outlets has a conveyance means 1 that conveys products 8 to be purchased, a reading means 2 that reads box codes printed on the products, a recognition means 3 that specifies the product names, quantities, and prices by the image read, referring to the read box codes by a merchandise control table 4, a computation means 5 that totals up the specified products and calculates the price to be paid, a display means 7 that displays the calculated monetary amount to be paid, and an exact-calculation means 6 that carries out the exact-calculation procedure by cash payment or a box-code prepaid card 10 according to the displayed price to be paid.