Conventionally, it was difficult to maintain parallelism between an optical filter and a PDP, and also the weight of the optical filter was put on the PDP.With a PDP 10 and a frame 30 separately fixed to a bracket 20 connecting to a leg member 60, fix an optical filter 80 to the frame 30. As a result, the optical filter 80 is fixed with required parallelism maintained with the PDP 10, and also the optical filter 80 and the PDP 10 will not put their weight on each other, thus eliminating unnecessary loads on the optical filter 80 and the PDP 10. Also, unnecessary flaws and distortions in a casing 40 can be prevented during the product manufacturing.