Provided is an optical pickup device that suppresses a fluctuation of a tracking error signal caused by stray light when recording/reproducing information on/from an optical disc including a plurality of recording layers and attains size reduction. It includes a laser diode 50 emitting laser light of about 405 nm in wavelength, an objective lens 2 irradiating the optical disc with an optical beam emitted from the laser diode and having a numerical aperture of about 0.85, and a light detector 10 including a detection part receiving the optical beam reflected from the optical disc. An optical magnification from the optical disc to the light detector 10 is set within a range from about 10 to 15.