A method of managing an address book of an image forming apparatus that supports a peer-to-peer (P2P) connection includes connecting the image forming apparatus to an external wireless device in the P2P connection method through a wireless local area network (WLAN); operating a soft access point (AP) module of the image forming apparatus so that the image forming apparatus operates as an AP; allocating an internet protocol (IP) address to the wireless device by driving a dynamic host configuration protocol (DHCP) server unit (DHCP server) of the image forming apparatus; and registering the wireless device connected to the image forming apparatus in the address book, which stores wireless devices that are connectable to the image forming apparatus, with the allocated IP address.