An exhaust port shutter apparatus which is attached to an exhaust port of a projector, includes: a guide section in which a first guide groove is provided; louver boards each having a turning shaft pin, the louver boards in which each turning shaft pin is formed so as to have a length which allows the turning shaft pin to pass through the first guide groove and project to the outside of the guide section; and a cam roller that has a cam groove on a peripheral surface thereof, the cam groove into which each turning shaft pin fits, the cam roller that can reciprocate, by rotation thereof, each turning shaft pin by the cam groove along the first guide groove in a first direction, wherein the louver boards are rotated at a necessary angle as a result of the cam roller being rotated and open and close the exhaust port.