A wireless mesh network system includes a plurality of wireless devices and is adapted to forward a message packet. Each of the wireless devices includes a transmitter, a receiver, a communications controller, and a RAM. Further, the communications controller detects a reception completion time of a message packet received, and controls such that, if the wireless device had performed forwarding the message packet received right before, a carrier sense time, which is the time from the reception completion time to the forwarding start, is set to be longer than a previously set carrier sense time, and if the corresponding wireless device had not performed forwarding the message packet received right before, the carrier sense time is set to be shorter than the previously set carrier sense time.