Abstract: There is provided an optical pick-up used for recording data to and/or reproducing data from at least three types of optical discs having at least two different thicknesses of cover layers. The optical pick-up includes light sources and an objective lens. A thickness t1 of a first optical disc, a thickness t2 of a second optical disc, and a thickness t3 of a third optical disc satisfy a relationship t1?t2<t3. A numerical aperture NA1 for the first optical disc, a numerical aperture NA2 for the second optical disc and a numerical aperture NA3 for the third optical disc satisfy a relationship NA1?NA2>NA3. Further, a first light beam for the first optical disc is incident on the objective lens as a converging light beam, and the second and third light beams for the second and third optical discs are incident on the objective lens as diverging light beams, respectively.