An optical pickup device is provided which includes a first diffraction grating (45) that splits a light beam emitted from a light-emitting/-detecting element (31) into a zero-order light beam and positive and negative first-order light beams, a second diffraction grating (46) that diffracts return light from an optical disk (2) for traveling along a light path separate from that of the outgoing light, and a third diffraction grating (47) that corrects the deviation of the light path by diffracting the positive first-order light beam diffracted by the second diffraction grating (46). The light-emitting/-detecting element (31) provides a focusing error signal FE by detecting the negative first-order light beam, and a tracking error signal by detecting return portions of the positive and negative first-order light beams from the first diffraction grating (45).