To provide a liquid crystal projector at a low cost, which has the image quality less degraded even when having a color separation part arranged in an off-axis system.

A color separation optical system 31 of a projection unit of the liquid crystal projector comprises a color separation prism 41 and a light angle correction prism 42. The color separation prism 41 is a cross dichroic prism having two dichroic faces arranged crosswise. The color separation prism 42 is arranged in such an off-axis system that an optical axis 24a of an illumination optical system 24 and a face V perpendicular to the dichroic faces are not parallel. An incidence angle correction prism 42a is arranged on an incidence face of the color separation prism 42. The incidence angle correction prism 42a corrects the angle of incidence on the color separation prism 42 of illuminating light by refracting the optical axis 24a, so that the optical axis of incident light and the perpendicular face V may approximate to parallel.