In a message processing system, a plurality of vehicles or other locations are equipped with message processing devices and transmit and receive a message. Preferably, the conductive lines, formed by a double metal process, are recessed into a supporting material that has a substantially planar surface. Therefore, even when a flow amount of refrigerant flowing into the nozzle is changed, it can prevent a vertical shock wave from being generated by suitably adjusting both the opening degrees of the throat portion and the opening degree of the outlet of the nozzle. The interface region connects the first type metal lines to first word lines in a first group, and connects the second type metal lines to second word lines in a second group.