A light control unit comprises: a substrate; an insulating film; a first transistor; a reflecting film formed on the insulating film; a light modulating film formed on the reflecting film; a plurality of pairs of electrodes arranged two-dimensionally on the light modulating film; and a polarizing plate formed on a first electrode. Here, the light modulating film is made of a material that varies in refractive index in accordance with the intensity of an electric field applied thereto. For such a material, PLZT containing Pb, Zr, Ti, and La as constituent elements may be used.