A disk-drive magnetic circuit fixing structure and fixing method for fixing a magnetic circuit to a base by means of a plurality of screws, wherein provisions are made to substantially prevent a microscopic sliding movement involving impulsive vibration from occurring at a fastening portion between the magnetic circuit and the base. More specifically, in a disk drive including a disk enclosure having a base and a cover, a magnetic head contained within the disk enclosure, and a driving coil motor for driving the magnetic head by working in combination with an actuator on which the magnetic head is mounted and a magnetic circuit disposed in the vicinity of the actuator, the magnetic circuit is fixed to the base with a single or a plurality of screws by applying in advance a lubricant forming a lubricating layer on a face where each screw contacts the magnetic circuit or the base.