A panel of a plasma display apparatus includes a front substrate and a back substrate arranged in opposition to this front substrate, and an outer circumferential portion of the front substrate and an outer circumferential portion of the back substrate are adhered to each other by a sealing material. The invention particularly but non exclusively concerns the fire protection against flames andor said flammable substances, such as oil or Molotov cocktails, as well as a high solvent andor acid resistance, especially in hostile environments. The customizable product class includes a set of one or more attributes to define the customizable product class. The filter unit is for providing a change in the output voltage over a predetermined period of time. Semiconductor device are fabricated by forming a first gate pattern on a first gate insulation layer formed on a first active region of a semiconductor substrate.