A disk device includes: a disk detecting member 17 pushed and moved by a disk; a rotation body 20 driven by the movement of the disk detecting member 17 to move a slide member 11; a tubular body 23 provided coaxially on the surface of the rotation body 20 and having an axially cutaway section; and an arm section 24 provided on the slide member 11 and abutted against the peripheral surface of the tubular body to cause the moving force exerted on the slide member 11 to act on the center of the rotation body 20.
