Embodiments of the present invention improve the safety against a fall of a disk drive device. In one embodiment, when an HDD has recognized detection result data of a fall sensor to indicate a fall, the HDD unloads a head slider from above a disk to a stand-by position. The HDD checks whether or not the detection result data of the fall sensor indicates a fall on the occasion of a seek start. If the data indicates a fall, the controller unloads an actuator. The HDD issues a seek fake error on the occasion of a seek completion. On the occasion of a re-seek start in the error recovery process, the HDD conducts a fall check referring to the detection result data.