MAGNETIC DISK DEVICE

PROBLEM TO BE SOLVED: To prolong the lifetime of a magnetoresistance-effect element by reducing the time in which a sense current is made to flow through the magnetoresistance effect element, as far as possible at the time of in the state of operation waiting in which there is no data access command from a host device in a magnetic disk device. SOLUTION: When the magnetic disk device is in an operation waiting state, feedback control for positioning a carriage is released, and the flowing of a sense current through a magnetoresistance effect element for an MR head is stopped. A current or voltage flowing a voice coil motor is detected subsequently without using servo information to be read from the MR head, and speed is controlled. When an interface and control circuit 11 recognizes no command from a host device and the magnetic disk device in the operation waiting state, a servo control circuit 12 releases the feedback control for positioning. A selection control circuit 6 for a mode or the like controls a recording reproducing amplifier 5 so that the sense current is not made to flow through the magnetoresistance effect element of the MR head.