A projection type image display apparatus of the present invention includes: a light source; a polarization selective reflection element having a function of reflecting or transmitting a light beam from the light source in accordance with a polarization direction thereof; and an element for modulating a polarization plane of an incident light beam in accordance with an image to be displayed. The polarization selective reflection element is film-like and has an optical transmission axis and an optical reflection axis. The polarization selective reflection element transmits a first linearly polarized light beam, and reflects a second linearly polarized light beam having a polarization plane orthogonal to a polarization plane of the first linearly polarized light beam, regardless of a direction of incidence of a light beam with respect to the polarization selective reflection element.