A wireless connection establishment method of an image forming apparatus using a mobile terminal is provided. The wireless connection establishment method includes, while the image forming apparatus is operating in a wireless fidelity (Wi-Fi) Direct mode, receiving a request to switch to a wireless setup mode, terminating the Wi-Fi Direct mode and connecting to a mobile terminal by entering the wireless setup mode, receiving access point (AP) connection information from the mobile terminal, establishing a connection to an AP by using the received AP connection information, and starting the Wi-Fi Direct mode.