In a conventional polarization beam splitter, it has been difficult to improve the angle-dependence characteristic of polarized beam splitting efficiency even if the number of layers is increased. The polarization beam splitter of the present invention is a polarization beam splitter having a polarized beam splitting layer having structure in which a plurality of gratings parallel to a first direction are periodically disposed in a second direction orthogonal to the first direction, and of light incident on the polarization beam splitter, chiefly light of a polarized component parallel to the first direction is transmitted therethrough, and chiefly light of a polarized component parallel to the second direction is reflected.