An optical pickup has a semiconductor laser, a diffractive optical element that has first diffraction regions and second diffraction regions and diffracts a beam emitted by the semiconductor laser, an objective lens that focuses the diffracted beam on an optical disc, and a detection unit that detects a tracking error signal using the diffracted beam reflected by the optical disc. When a zero order diffraction beam is focused on the optical disc, a first order diffraction beam is diffracted by the first diffraction regions to be focused at a position between the objective lens and the optical disc, and diffracted by the second diffraction regions to be focused at a position beyond the optical disc. The first order diffraction beam has a beam width that, on the optical disc in a radial direction thereof, is two times or greater a track pitch of the optical disc.