PURPOSE: To quickly make access to a disk device by rotating the motor of the disk device when a data input possible state is detected by meas of a sensor and, in the mean time, by stopping it when a prescribed time elapses after it is detected that the state is not the input possible one.

CONSTITUTION: The sensor 2 is arranged in an input device. When the sensor 2 detects that the hand of an operator comes close to an area for operating the input device 1, a disk controller 5 starts the motor of the disk device 6 so as to make access. In the meantime, when measurement time is set in an input judging means 3 by a timer 4 so that the sensor 2 provided in the input device 1 detects that the hand of the operator is not in the input possible state after the prescribed time elapses, the motor of the disk device 6 is stopped. Thus, access to the disk device is quickly made.