A projection type image display apparatus which includes an arc lamp for emitting light rays by arc discharge, a reflecting mirror for reflecting the light from the arc lamp, the light rays being made parallel by an optical means such as a condenser lens, and projected into a transmissive display panel. The parallel rays are focused by the microlens array in the respective picture elements. The light rays through the transmissive display panel are projected onto a screen. The arc of the arc lamp is directed perpendicularly to the optical axis of an optical system so that the light rays are made parallel with the optical axis by the optical means.