An optical pickup includes a light source which emits first and second lights having different wavelengths for a first recording medium and a second recording medium having a relatively large thickness, respectively, an optical path changer which alters a traveling path of incident light, and an objective lens which focuses the first and second lights on the recording medium. While the light source emits the first light, a photodetector is adjusted to be aligned with the optical axis for the first recording medium. The light source and/or a sensing lens are adjusted in the direction of the optical axis, and the tilt of the objective lens is adjusted. Next, while the light source is operated to emit the second light, the light source is adjusted in a rotating direction. As such, an optical axis alignment is completed for the first and second recording media.