An information setting method for a setting device includes the following processes. A first certificate and identification information are obtained from a wireless device to be caused to join a wireless network managed by a management device. The first certificate certifies that the wireless device is a formal wireless device and includes a first public key. The identification information is information that identifies the wireless device. A second certificate is obtained from the management device. The second certificate certifies that the management device is a formal management device and includes a second public key. Apparatus information required for the wireless device to join the wireless network is encoded using the first public key and is output to the wireless device. Management information including the apparatus information and the identification information associated with the apparatus information is encoded using the second public key and is output to the management device.