When light from a reflection image display element is incident on a polarization split surface at an angle other than 45°, leakage light that decreases the contrast of an image is produced. In a projection image display apparatus which illuminates an image display element with light from a light source and projects light from the image display element through two polarization split surfaces, when the angles of first and second light rays, of light rays incident on the polarization split surface, with respect to the optical axis correspond to 55% of the maximum angle of the incident light rays with respect to the optical axis, where light rays of which incident angle with respect to said image display element is larger is set as first light ray and light rays of which incident angle with respect to said image display element is smaller is set as second light ray, and a light shielding characteristic value L on the two polarization split surfaces is represented by L=[(M1)a·(M1)b+(M2)a·(M2)b]/2 where (M1)a is the amount of leakage light of the first light ray on the polarization split on the reflection image display element side, (M2)a is the amount of leakage light of the second light ray, (M1)b is the amount of leakage light of the first light ray on the polarization split on the projection optical system side, and (M2)b is the amount of leakage light of the second light ray.