A disk device includes a magnetic disk having a data non-recording region, and a data recording region inside the data non-recording region, a plurality of heads configured to read and write information from and onto the magnetic disk, and a plurality of arms supporting the heads, the arms being rotatable to move the heads from a parked position to a desired data recording position above or below the magnetic disk. Each of the arms comprises an overlapping region that overlaps the data recording region of the magnetic disk in a thickness direction of the magnetic disk when the heads are at the parked position.