Surface inspection apparatus includes stage for holding substrate, light source, scanning optical system for scanning light from the light source along first direction for plural times, stage scanning mechanism for scanning the stage in second direction intersecting with the first direction, and detector for detect scattered light from the substrate Inspection target region of the substrate is scanned by the light from the light source by an operation of the scanning optical system and the stage scanning mechanism. Chromatic aberration of the scanning optical system is corrected to fall within predetermined wavelength range. Fluctuation range of wavelength of the light from the light source is determined based on variation in total lighting time of the light source in scanning period of each light scanning operation along the first direction. The fluctuation range falls within the predetermined wavelength range.