Abstract: A plurality of filaments are stretched in parallel on a rear plate, and an insulating plate is provided so as to cover the filaments. In the insulating plate, a plurality of through-holes are formed along the longitudinal direction of the respective filaments for exposing parts thereof. Each through-hole and phosphor layers, which are provided on the insulating layer adjacent to the through-hole, constitute one unit picture element. The respective phosphor layers in the respective picture element are installed in a plurality of cavities formed in a rib provided on a lower surface of the insulating plate, whereby separated from the neighboring phosphor layers. The respective cavities function as a discharge room, with a light-transmissive front plate, formed on the rib, as a lid and a portion of the insulating plate corresponding to the phosphor layer as a bottom. The respective discharge rooms overlap the through-hole at one end in the longitudinal direction thereof.