Conventionally, when a thickness of a dielectric layer is reduced without changing an electrode shape, a drive margin is reduced and stable driving cannot be performed. In a discharge cell, a display electrode comprises a projection extending in a column direction from an electrode body extending in a row direction, the projection forms a discharge gap together with an adjacent paired projection of the other display electrode, the projection includes a first projection and a second projection having two kinds of widths in a row direction, and when a ratio of widths of the second projection on the discharge gap side to the first projection on the electrode body side is assumed as Y and a thickness of the dielectric layer as X, Y.ltoreq.0.2X, X.ltoreq.20 and Y.gtoreq.0.5 are satisfied.