A wireless relay device that performs relay of encrypted data over a wireless network, the wireless relay device, includes: a determiner that determines whether or not there is an abnormality using first data which is transmitted to its own device from wireless devices belonging to a preset section among wireless devices joining the wireless network; a transmission controller that transmits second data indicating a result of the determination of the determiner to a preset transmission destination; and an encryption processor that decrypts the first data and encrypts the second data transmitted by the transmission controller.