A printing device of the present invention has an additional function of switching over connection with two wireless networks. The printing device enters a user's wireless LAN based on first setting information, while establishing connection with a maker's wireless LAN based on second setting information to communicate with a printer, which is one of additional devices newly entering the user's wireless LAN. In response to a requirement from the printer, the printing device temporarily disconnects from the user's wireless LAN and enters the maker's wireless LAN to transmit setting information relating to the user's wireless LAN to the printer. This arrangement desirably relieves the labor of the user for settings in the additional devices to establish connection with the wireless network.