An optical disk device for use as a mass storage device includes an axially and angularly movable support mounted on a hollow shaft and supporting a condensing lens that converges a laser beam onto an optical disk mounted in position. A substantially cylindrical side yoke is disposed concentrically around the hollow shaft, and a magnet is coupled to said side yoke, the magnet and the side yoke jointly providing a magnetic circuit. A tracking coil is mounted on the support, the side yoke extending through the tracking coil in magnetically coacting relationship to the magnetic circuit. When an electric current flows through the tracking coil, the support and hence the condensing lens are angularly moved in a wide angular range about shaft to access a desired track on the optical disk. The condensing lens is disposed off the shaft, but is spaced from the shaft by a relatively small distance. Therefore, the moment of inertia of the support with the condensing lens supported thereon is relatively small for quick tracking control and short track access time.