The present invention provides a polarization beam splitter including a
multilayer film formed by laminating a first layer having a refractive
index in a first range, a second layer having a refractive index in a
second range which does not overlap the first range, and a third layer
having a refractive index in a third range which does not overlap the
first or second range in the order of the first layer, the second layer,
the first layer, and the third layer in succession, wherein the
transmittance of s-polarized light is 60% or more higher than the
transmittance of p-polarized light in a first wavelength region, the
transmittance of p-polarized light is equal to or higher than 70% in a
second wavelength region different from the first wavelength region, and
each of the first wavelength region and the second wavelength region has
a bandwidth equal to or larger than 30 nm.