A wireless LAN setting system mounted on an image forming apparatus that performs network connection through a wireless LAN and used for performing wireless communication with plural terminals, the wireless LAN setting system including a mode for checking, before setting is performed, existing setting contents (setting items and setting states) presently set. Guide indications are attached to respective setting screens. With the wireless LAN setting system, proper determination is performed and setting operation is correctly performed even if a user (an administrator) does not have professional knowledge.