A spatial light modulator is constructed from a conductive silicon mirror substrate and a glass electrode substrate including sodium, anode-bonded together. The silicon mirror substrate has micromirrors arranged in a matrix, torsion bars coupling these micromirrors in the x-direction, and a frame coupled to both ends of the torsion bars. A glass electrode substrate has a central depression, a rim around the periphery thereof, pillars projecting from within the depression, and electrodes and wiring driving micromirrors formed within the depression in an inclining manner. Both ends of the torsion bars are bonded to the rim of the frame portion, and intermediate portions of the torsion bars are bonded to the pillars. Both ends of the torsion bars are cut away from the frame portion during dicing.