A surface inspection apparatus, which includes a detecting device of scanning a surface of an inspection object with an inspection light and outputting a signal corresponding to a light amount of refection light from the surface, generates a two-dimensional image of the surface of the inspection object on the basis of the output signal of the detecting device (S1), classifies pixels contained in the two-dimensional image into a first group of pixels having tones corresponding to defects on the surface of the inspection object and a second group of pixels having tones not corresponding to the defects, extracts the first group of pixels as a defect candidate part for each region surrounded by second groups of pixels (S3 to S5), discriminates a defect candidate part larger than a prescribed size as a defect (S6), inspects the two-dimensional image for each specific inspection region, and identifies an inspection region as a defect region, in which density of defect candidate parts that are smaller than the prescribed size is equal to or more than a prescribed level (S7, S8).