In this disclosure, there is provided a polarization element comprising a substrate having a predetermined light transmittance in a predetermined wavelength region and a plurality of polarization portions having a wire grid structure on the main surface of the above substrate, wherein the plurality of polarization portions are arranged to ensure that the ratio of the total area of the polarization portions to the predetermined area of the main surface gradually changes along a predetermined direction so that at least one of light transmittance and polarization degree gradually changes in the predetermined direction on the main surface of the substrate. A method for manufacturing the polarization element is also disclosed.