To provide an inexpensively introducible commodity control system capable of reducing a cost of a using terminal, and capable of complete real- time processing.

This commodity control system has a server computer 5 having an authenticating means for authenticating the portable terminal 2 having a means 3 for reading a bar code, and controls a commodity by using the bar code attached to the commodity. The server computer 5 comprises a storage means (unillustrated) for storing an image screen information group required for the portable terminal 2 to control the commodity, a means for transmitting image screen information according to the processing content executed by the portable terminal 2 authenticated by the authenticating means to the portable terminal 2 by reading out the image screen information from the storage means, a receiving means for receiving information processed and transmitted by the portable terminal 2 by using the transmitted image screen information, and a registering means for registering the received information.