PURPOSE: To simply and exactly calculate the selling price of the merchandise consisting of various ingredients by allowing a selling data calculating means to add all unit price data decided by a sub-merchandise decision means and unit price data decided by a main merchandise unit price reading means.

CONSTITUTION: A RAM 13 is provided with a main merchandise data storage means storing the merchandise data such as the merchandise code, names, multipliers, unit price, status for each dough of various sizes as main merchandise and each ingredient put on the material as a sub-merchandise and a setting table 13a as a sub-merchandise storage means. It is also provided with work areas A to C(13a to 13d). Take the pizza for instance, the multiplier is set to the setting table 13a according to the size of the dough, and the cost of the ingredients to be put on the dough of the size is calculated based on the multiplier. Thus, the selling price of the merchandise consisting of various ingredients or requiring processing can be easily and accurately calculated.