In a case of a connection destination of a master device in wireless communication not being registered in the master device, a smartphone, at the start of setting of the registration, determines a mode of wireless communication with the master device (specifically, a router connection mode or a soft AP mode) according to whether or not wireless communication is performed through a wireless router and acquires setting information related to the connection destination corresponding to the determined mode of wireless communication. The smartphone sends a message indicating that wireless communication will be performed in the determined mode of wireless communication and sends the setting information related to the connection destination corresponding to the mode of wireless communication to the master device. The master device registers the setting information that is sent from the smartphone and related to the connection destination corresponding to the mode of wireless communication.