An image forming apparatus includes a user interface unit that includes a scan area, an image reading unit that reads an image of a scan object disposed on the scan area, a driving unit that moves the image reading unit, a control unit that controls a function according to a position of the scan object, an operation performing unit that performs the function by using the read image, and a storage unit that stores information about the function corresponding to the position of the scan object. The scan area includes a determination area and a function area, and when it is determined that the scan object does not exist on the determination area, the control unit controls the operation performing unit to perform the function corresponding to the position of the scan object on the function area.