Abstract: In an optical pickup apparatus, including a laser source arranged along an optical axis, a polarization beam splitter and an objective lens, wherein light emitted from the laser source is emitted on a recording plane of an optical-magnetical recording media as a converged beam, light beams reflected from the recording media of the optical-magnetical recording media are separated by said polarization beam splitter to obtain a predetermined polarized light component, a phase change means, which changes a phase of light passing through one side of said optical axis and a phase of light passing through another side of said optical axis by a predetermined angle, such as 1/2 wavelength plate, a phase retardation type prism and a combination optical rotation plate, is provided between the polarization beam splitter and the objective lens, and, an optical detection element, which detects the light polarized by the polarization beam splitter, is provided at a side intersecting the phase change means of the polarizatio