A polarization element includes: a substrate; a plurality of convex line sections on one surface of the substrate and forming stripes in a plan view; and a multilayer thin line provided to each convex line section and extending along the convex line sections, wherein the multilayer thin line has a lower layer on the convex line section, and an upper layer stacked on the lower layer, the lower layer and the upper layer each have a first thin line on one side surface in a direction along a shorter dimension of the convex line section, and a second thin line on the other side surface, the materials of the lower layer first thin line and the upper layer first thin line are different from each other, and the materials of the lower layer second thin line and the upper layer second thin line are different from each other.