A multi function device includes a main board configured to control functions corresponding to a model of the multi function device and a sub board configured to be connected with the main board. The sub board carries out peripheral control corresponding to the model of the multi function device. Main board first identification information indicative of a category of the main board is obtained, and main board second identification information intrinsic to each model of the multi function device is also obtained. Then, the model of the multi function device is identified based on the main board first identification information and the main board second identification information when the multi function device is powered on. Further, function information corresponding to the identified model is obtained. The main board and the sub board of the multi function device are controlled based on the function information so as to function correctly.