To enable comprehensive display of a position of each device for a user by controlling positional information of each device connected with a network by hierarchical structure.

When a retrieval request of the device is made from a client device, a hierarchical position of the device the retrieval of which is requested is specified, the specified position of the device is comprehensively displayed for the user. When no map corresponding to a retrieval result exists, arrangement and registration to a desired position are enabled simply by performing visual operation on the desired position by controlling the positional information of each device connected with the network and providing a client device with map information. In addition, when the map information is displayed, the need for transfer of the map information from a server device to a client terminal is eliminated.