To provide a polarization element having good polarization properties and excellent in heat dissipation property and manufacturing costs. In order to solve the above problem, a polarization element 1 of the present disclosure includes a substrate 10 made of a transparent inorganic material; a grid structural body 20 which is made of a transparent material, and includes a base portion 21 provided along a surface of the substrate 10 and protruding portions 22 protruding from the base portion 21 in a grid; and an optical functional layer 30 which is formed on the protruding portions 22, and includes an absorptive layer for absorbing light, a reflective layer for reflecting light, or a multilayer having at least the absorptive layer and the reflective layer.