A wire grid polarizer including a substrate, parallel conductive wire patterns which protrude from a top surface of the substrate, non-conductive wire patterns which are formed on the conductive wire patterns, respectively, and a protective layer which is formed on the conductive wire patterns and the non-conductive wire patterns. The protective layer includes first transparent particles having a diameter greater than a period of the conductive wire patterns, and spaces between the conductive wire patterns are filled with air or are evacuated to form a vacuum.