To provide a system for a POS system eliminating the need for complex MACRO registering operation, thereby greatly improving operability while also enabling smooth and quick specific operations such as reporting and registering.

In the POS system which executes an article selling process, a reporting process about predetermined items, and a registering process about predetermined items, a characteristic function number is allocated to each function by which a predetermined specific process is performed. The characteristic function number and the corresponding function associated with each other are stored in a function table 3. In response to the designation of the function number corresponding to the specific process, the corresponding function is read from the function table 3 to execute the function read.