a front substrate and a rear substrate disposed to be facing each other;

a plurality of address electrodes and a plurality of display electrodes formed in a space between the front substrate and the rear substrate, the address electrodes and the display electrodes being arranged to cross each other;

a display area for forming an image;

a non-display area around the display area, the non-display area including a dummy region;

a plurality of barrier rib members, each barrier rib member extending across at least one of the display area and the non-display area, the plurality of barrier rib members including first barrier rib members and second barrier rib members, the first barrier rib members extending along a first direction and the second barrier rib members extending along a second direction that crosses the first direction, the first barrier rib members and the second barrier rib members partitioning the space between the front substrate and the rear substrate and defining a plurality of discharge cells in the display area and a plurality of dummy cells in the dummy region,

wherein the dummy region includes:

at least one first barrier rib region extending along the first direction, the first barrier rib region including portions of at least some of the plurality of barrier rib members;

at least one second barrier rib region extending along the second direction, the second barrier rib region including portions of at least some of the plurality of barrier rib members; and

at least one sector region, the sector region including at least one arc-shaped sector barrier rib member extending along a direction other than the first direction and the second direction and connecting at least one portion of at least one of the barrier rib portions in the first barrier rib region to at least one of the barrier rib portions in the second barrier rib region, the sector region further including a radial barrier rib member linearly extending from a point where the first barrier rib region and the second barrier rib region intersect to a point on a curve defining the arc-shaped sector barrier rib member.