To provide a polarizing beam splitter excellent in polarized beam splitting characteristics, and a reflection type liquid crystal projector device having high efficiency by using the polarizing beam splitter.

The polarizing beam splitter has first and second glass prisms having first and second end surfaces which become light incident surfaces or light emitting surfaces and an opposed surface as the side surfaces of a prismatic body, and a wire grid polarized beam splitting element constituted by forming a metal grating on either surface of the glass base plate. The surface of the wire grid polarized beam splitting element, where the metal grating is not formed, is stuck to the opposed surface of the first glass prism. The second glass prism is arranged so that its opposed surface may be opposed to that of the first glass prism to which the wire grid polarized beam splitting element is stuck in a state where an air layer is formed. Namely, the metal grating side is not brought into contact with the second glass prism side.