An optical modulator according to the present invention is configured at least by a semiconductor layer subjected to a doping process so as to exhibit a first conductivity type, and a semiconductor layer subjected to a doping process so as to exhibit a second conductivity type. Further, in the optical modulator, at least the first conductivity type semiconductor layer, a dielectric layer, the second conductivity type semiconductor layer, and a transparent electrode optically transparent in at least a near-infrared wavelength region are laminated in order.