Abstract: An optical pickup apparatus includes a device for recording and reproducing information by changing a laser beam emitted from a semiconductor laser to a parallel light and by irradiating the parallel light to an optical information recording medium sequentially through a deflecting prism and an objective lens, a device for performing focusing and tracking servo controls by guiding a reflected light from the optical information recording medium to a servo optical system sequentially through the objective lens and the deflecting prism again, and a device for setting the positions of the deflecting prism and the objective lens such that the length of an optical path from a deflecting point of the deflecting prism to a main point of the objective lens is ranged from the focal distance of the objective lens to a length twice the focal distance of the objective lens.