An optical pickup includes a first laser beam light source 1 for emitting a light flux of a first wavelength, a diffraction grating 5 and an optical device 6 having a second laser beam light source 7 for emitting a light flux of a second wavelength and a hologram element 8. In operation, the diffraction grating 5 diffracts the backward light of the first wavelength at a predetermined angle. The hologram element 8 diffracts the backward light of the second wavelength by a first area 8a and also diffracts the backward light of the first wavelength at a reversed-polarity angle to the first area 8a by a second area 8b.