To provide an optical filter which makes excellent ground contact with an electromagnetic wave shield function layer and a plasma display device which can be made thin.

A front film type sheet 3 is formed by laminating a reflection preventive film 3a and an electromagnetic wave shield film 3b. The electromagnetic wave shield film 3b is formed of, for example, an electromagnetic wave shield metal film. The electromagnetic wave shield metal film is positioned on not the surface side of the PDP 2, but on the opposite side. The electromagnetic wave shield film 3b is larger than the reflection preventive film 3a and the edge part (metal film formation side) of the electromagnetic wave shield film 3b is exposed to make the excellent ground contact.