An optical pickup apparatus for conducting at least recording or reproducing of information on two types of optical information recording media having protective substrates with different thicknesses, includes: a first light source for emitting a first light flux with a wavelength λ1; a first objective lens for converging the first light flux on an information recording surface of a first optical information recording medium when the optical pickup apparatus reproduces or records information for the first optical information medium; and a second objective lens for converging the first light flux on an information recording surface of a second optical information recording medium when the optical pickup apparatus reproduces or records information for the second optical information medium, wherein effective diameters of the first objective lens and the second objective lens are substantially same.