The data processing device 400 of this invention comprises a controller unit 402, a data recorder unit 404, a display unit 406, a data input unit 408 and a communication control unit 410. By transmitting a request for service in a multiple-address way to a plurality of devices on a network and selecting a service providing device, communicability with the service-providing group can be automatically obtained without prior registration of device information in the respective devices or in any specified device. If the service providing device withdraws from the network or a trouble develops in the communication link, a new service providing device is selected from among other communicable devices.