According to one embodiment, a disk device includes a disk, a head that performs data read/write processing on a recording region of the disk, a controller that performs a media scan processing for detecting the presence or absence of a defect in a sector in the recording region of the disk in track unit. When the controller performs the media scan processing on a first sector and a second sector arranged in the track, and a third sector arranged between the first sector and the second sector, the controller performs skip processing in which the controller scans the first sector and the second sector, and does not scan the third sector.