It is an object of the present invention to improve reliability to a dust or the like of a magnetic disk device. The magnetic disk device of the present invention comprises a magnetic disk 10, a levitation type magnetic head slider 12 and a controller 14 for controlling an operation of the magnetic head slider 12 and the controller 14. The controller 14 moves the magnetic head slider 12 to a CSS (Contact Start Stop) region of the magnetic disk 10 at a predetermined time interval and performs a CSS operation at least once.