A multi-function device connected to a computer includes a printer for printing on a recording paper, a modem for making facsimile communication, an interface for receiving printing data from the computer, a memory commonly used for the printer and the modem, and a controller for controlling the printer and the modem. The controller determines a capacity remainder of the memory. Further, the controller slows down a speed of receiving printing data from the computer upon determination that the capacity remainder of the memory is below a predetermined level while both of the printer and the modem are in operation.