An optical filter for a display device includes a transparent substrate; an electromagnetic shielding layer in which a high refractive metal oxide layer and a metallic layer are layered, the electromagnetic shielding layer being layered on the transparent substrate; and a grounding conductive film layer for grounding the electromagnetic shielding layer, the a grounding conductive film layer being layered on the electromagnetic shielding layer. The optical filter can improve the ability to block electromagnetic waves.