A surface inspection apparatus (100) comprises a light (10) source for emitting a light beam L0, an optical illumination system (30) for projecting the light beam on an inspected surface (220) formed by a film 210, an optical detection system (50) having lenses to spatially split reflection lights and an aperture stop (60) having apertures disposed with polarization elements (61 64) for transilluminating mutually different polarized light components, a light intensity detection device (41 44) for individually detecting the light intensities of the respective reflection lights passed through the respective polarization elements, a scanning device (20), and an arithmetic processing device (70) for detecting the polarization conditions of the respective reflection lights and obtaining a film thickness of the film and at least one of the physical properties of the film.