PURPOSE: To issue order slips corresponding to the priority order of printing by rearranging commodity order data in a prescribed order by generating codes with a read sorting code as a high-order digit and with an inputted commodity code as a low-order digit.

CONSTITUTION: Various kinds of commodities are stored in a sorting code storage part 22 corresponding to commodity codes. When reading the sorting code corresponding to the commodity code, a customer code stored in a first area WK 1 of a work memory 24 and a link section code and the commodity code stored in a second area WK 2 are read out. Then, the synthetic code is prepared by generating the link section code and the commodity code at the low-order digit while setting the customer code at the most-significant digit and stored in fourth and fifth areas WK 4 and WK 5. With the generated code stored in these areas, the commodity order data are rearranged in the prescribed order and stored in an order data storage part 23. Therefore, the commodity order data are stored in the order data storage part 23 while being arranged in the order of sorting codes or in the order of commodity codes in the case of the same sorting.