An optical head device that converges first and second laser beams having different wavelengths on recording surfaces of first and second optical recording media through a single light converging optical system including an objective lens for recording or reproducing data on the recording surfaces. A refracting surface of the objective lens is divided into two regions, i.e., a central refracting surface region with an optical axis thereof being as a center and an outer circumferential refracting surface region that surrounds an outer circumference of the central refracting surface region. A diffraction grating is formed generally entirely over the central refracting surface region. When recording or reproducing data on the first optical recording medium using the first laser beam, a beam spot is formed with a diffracted beam obtained by the central refracting surface region. When recording or reproducing data on the second optical recording medium using the second laser beam, a beam spot is formed with a beam portion that passes the outer circumferential refracting surface region and a diffracted beam obtained by the central refracting surface region.