An image forming apparatus and a method of controlling the same, the image forming apparatus including: a toner cartridge including a memory to provide first authentication information, and an authentication key circuit to provide a second authentication information; and a controller to authenticate the toner cartridge when the first authentication information and the second authentication information are identical. Furthermore, the controller intentionally destroys the first authentication information or the second authentication information when there is no toner in the toner cartridge. Accordingly, it is possible to prevent an unauthorized use of the toner cartridge, and thus to perform an ideal print operation.