To provide a wireless network system capable of selecting optimal gateway from among a plurality of gateways and obtaining interconnection among networks.

The wireless network system carries out interconnections among wireless network and networks of different types. The system comprises a plurality of wireless nodes constituting the wireless network, a control device connected to the networks of different types, and a plurality of gateways interconnecting the wireless network to the networks of different types; and a wireless node searches for path from among a gateway candidate list, selects the gateway of the optimum path, based on the information collected during path searching, and transfers data to the control device via the gateway of the optimum path.