A wire grid polarizer has a resin substrate having grid-shaped convex portions, a dielectric layer provided to cover the grid-shaped convex portions of the resin substrate and at least part of side faces of the portions, and metal wires provided on the dielectric layer. The wire grid polarizer has a microstructural concavo-convex grid structure having grid-shaped convex portions, is not limited in structure, and has both the excellent degree of polarization and excellent transmittance over a wide range in the visible region.