When a semiconductor laser is arranged outside a slider and a light is to be guided to the slider through a waveguide, the following problems will be solved: the stability of the flying slider is deteriorated due to a stress from the waveguide; and when an actuator is arranged near the flying slider, the motions of the slider are hindered by the waveguide. A waveguide for guiding a light to a light irradiating unit inside a slider, which floats over a medium and has the light irradiating unit for irradiating a light to the medium; and a waveguide for propagating a light from the light source to the waveguide inside the slider, are included. The two waveguides are not in contact with each other, and a relative portion between the two waveguides is movable.