An optical modulator holder (4402) has an optical modulator holding unit (4405) having a substantially rectangular U-shaped cross-section and made of heat-conductive material, a plate-like member (4406) made of heat-conductive material, and an optical modulator cooling unit (4407) constituted by a hollow member which is capable of enclosing cooling fluid inside and is made of heat-conductive material. Of the optical modulator holding unit (4405) and the plate-like member (4406), peripheries of openings (4405A1, 4406A) each contact heat-transferably a liquid crystal panel (441). The liquid crystal panel (441) is held inside the rectangular U-shape of the optical modulator holding unit (4405). The optical modulator cooling unit (4407) is formed like a ring whose inner side surface heat-transferably contacts the liquid crystal panel (441), and has an inlet port (4407D) and outlet port (4407E).