PURPOSE: To provide a means capable of executing adjustment, change, etc., in a specified money unit while executing sales management at a selling time.

CONSTITUTION: A POS terminal 17 having an input part 11 allowing a user to input data to the POS terminal 17, a calculation part 12 for executing calculation based upon the input, a storage part 13 for storing the input and a calculated result, a display part 14 for displaying the input and the calculated result, and a printing part 15 for printing out a receipt is also provided with a money unit specifying function 21 for specifying a money unit, a money unit converting function 22 for converting each money unit into an 'YEN' unit, a correspondence table 23 recording conversion rates for money unit conversion and a conversion specifying function 25 for specifying conversion and the function 22 converts a money unit specified by the function 21 and 'YEN' in accordance with the conversion rate recorded in the table 23 by the instruction of the function 25.