A polarizing plate includes a substrate and a conductive pattern layer including a first pattern and a second pattern. The first pattern includes line-shaped structures disposed at intervals with a period shorter than a wavelength of incident light to be isolated from one another, the first pattern configured to transmit first polarized light of the incident light therethrough and reflect second polarized light of the incident light that is perpendicular to the first polarized light. The second pattern is disposed on an outer boundary of the first pattern, the second pattern isolated and insulated from the first pattern, the second pattern including a stem and at least one branch protruding from the stem toward the first pattern.