A power supply control device is configured to reduce a current supplying capacity required by a power supply even when power is supplied to a prescribed external device. The power supply control device comprises a first power supply for supplying power to a pointer instrument; a first control unit that operates with power from the first power supply and controls driving of the pointer instrument and supply of power from the first power supply to the pointer instrument; and a second control unit for controlling supply of power from the first power supply to an external memory. Upon receiving a prescribed command, the first power supply stops supplying power to the pointer instrument, and the first power supply starts supplying power to the external memory in response to the stoppage.