A wireless mesh network system includes a plurality of wireless devices adapted to forward a message packet. Each of the wireless devices includes a transmitting unit, a receiving unit, a communications controller, and a RAM. Further, the communications controller controls such that an original source address contained in a message packet forwarded by a wireless device, which is an address of the wireless device that has firstly transmitted the message packet, and a packet number that identifies the message packet are stored in the RAM, and controls such that a message packet received is forwarded if information contained in the message packet received is not consistent with information of the original source address and the packet number stored in the RAM.