The invention, receiving a camera operation screen request from a client terminal, determines a code to be transmitted to the client terminal and transmits the code to the client terminal together with camera operation screen information, registers to a memory a code attached to a drive request signal transmitted from the client terminal, and, receiving a drive request signal from a client terminal, controls the camera in accordance with the signal in case a code matching a registered code is included, and rejects the drive request in case a code matching the registered code is not included. With this configuration, when a plurality of users operate a common camera unit via a network, a code determined by the camera unit is returned from a client terminal and the client terminal is identified based on whether the code is matching. This eliminates the needs for issuing a special id for identifying a client terminal and allows easy operation anywhere from the network by using a general-purpose browser.