A wire grid polarizer has mainly a resin substrate 1 having grid-shaped convex portions 1a, a dielectric layer 2 provided to cover the grid-shaped convex portions 1a of the resin substrate 1 and at least part of side faces 1b of the portions, and metal wires 3 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.