Disclosed herein are an electrostatic-type variable diffractive light modulator, which includes lower micromirrors that are provided on a glass substrate to be spaced apart from each other, and actuates upper micromirrors that are spaced apart from the substrate by an electrostatic actuating method, thus allowing the upper and lower micromirrors to diffract incident light entering a lower portion of the substrate, and a method of manufacturing the electrostatic-type variable diffractive light modulator.