A structured polarizer includes a substrate including a dielectric material including elongated metal particles embedded to form a polarizing layer including a plurality of first polarizing regions having first elongated metal particles collectively aligned along a first direction and a plurality of second regions having second metal particles, the first polarizing regions and the second regions adjoining each other, the first metal particles being in the same plane as the second metal particles, a degree of polarization with respect to the first direction in the first polarizing regions at between 0.5 μm and 1 μm from a boundary between the first polarizing regions and the second regions being more than 90%, and a degree of polarization with respect to the first direction in the second regions at between 0.5 μm and 1 μm from the boundary between the first polarizing regions and the second regions being less than 10%.