A multifunctional processing apparatus is comprised of a first controller for controlling the operation of exercising a plural number of functions, a connector, to which a second controller for controlling the operation of exercising the same function as at least one of the plural number of functions is connected, a recognizer for recognizing the connection of the second controller to the connection means, and a control selector for causing one of the first and second controllers to control one function upon recognition of the connection by the recognizer.