To make performable efficient business activity by allowing a selling person to be able to suitably refer to stock information recorded in a host computer in real time even from the outside of the office.

A stock managing system sues the host computer to sequentially update and record information such as stock, ordering, order receiving based on information inputted from the outside. A portable telephone for communication using a packet communication network is allowed to connect to the host computer through the Internet, and stock information recorded in the host computer can be displayed on an image of the portable telephone.