An image forming apparatus which makes it possible to provide restricted access thereto without requiring an information processing apparatus to have a special authentication function. The image forming apparatus receives authentication information input by a user using a user interface, and receives a connection request transmitted from the information processing apparatus. When receiving the connection request, the image forming apparatus determines whether or not the user has been authenticated based on the received authentication information. If the user has been authenticated, the image forming apparatus permits execution of processing from the information processing apparatus thereto, whereas if not, it refuses execution of processing from the information processing apparatus.