An object of the present invention is to provide a method of fabricating a substrate, and the like which excels in flatness, ten-point average roughness and surface roughness of substrates and flattens and smoothes the substrate surface. The method of fabricating a substrate includes a step of correcting flatness, a step of correcting surface unevenness in which the substrate surface is polished by means of a polishing pad with a hardness defined by JIS K 6253 of 70 or more, and a step of finishing surface roughness, to therefore achieve the above objectives. Such a substrate can be used for masks and mirrors of semiconductor exposure, discs for flying height tests of the hard-disk magnetic heads, and pharmaceutical test preparation, and the like.