An optical disk device performing data reproducing and/or data recording of a disk with the disk being clamped and rotated. The disk device has a simple structure in which light emitted from an optical pickup can be securely made incident on the disk at right angles. The disk device includes the optical pickup for reproducing or recording on the disk clamped by a clamping mechanism, and an optical pickup driving mechanism. The optical pickup includes a guided part. The optical pickup driving mechanism includes a guide shaft for guiding the movement of the optical pickup via the guided part of the optical pickup. The center axis of the guided part is shifted from the direction perpendicular to the direction of light emitted from the optical pickup so that the direction of light emitted from the optical disk can make an approximately right angle with the disk surface.