In order to understand the discharge phenomenon within a plasma display panel (PDP) cell thoroughly and in particular its three-dimensional effect, the three-dimensional measurement should be taken and studied. Thus, the scanned point detecting system, which consists of an optical microscope with a point detector and a scanning stage, is proposed for the spatial three-dimensional measurement of the light emitted from Ne-Xe (4%) PDP. The characteristics of the three-dimensional discharge phenomenon are analyzed by using the proposed system. From the intensity distributions of 600 nm wavelength light, it is shown that the light which is detected at the inside edge of an indium tin oxide electrode is stronger than any other points and the light intensity which is detected at the center between the barrier ribs is stronger than near the barrier ribs. Also, the 828 nm light shows a broad distribution which reaches the outside edge of the bus electrode. The reason is that the 828 nm light is emitted from Xe* (2p(5)) state which is easily excited by the weak electric field. Finally, we found that the intensity of 450 nm blue phosphor light located at the upper side of the barrier ribs is stronger than the bottom side. (C) 2003 American Vacuum Society.