The present invention makes possible a compact optical pickup device that eliminates effects due to the position where a sub beam is projected during tracking compensation, and provides for stable tracking compensation.A diffraction grating 12 in the optical pickup device PU gives an astigmatism to a sub beam (either of ±1-dimensional light), and shines that sub beam onto an optical disc DK. Also, a tracking error signal Ste is obtained by subtracting a push-pull signal PPsub that corresponds to a sub beam from a push-pull signal PPmain that corresponds to a main beam (0-dimensional light), and tracking compensation is performed based on that tracking error signal Ste.