A plasma display panel (PDP) comprises: a front substrate and a rear substrate which face each other; and a barrier wall which is interposed between the front substrate and the rear substrate, which includes base portions arranged on either side of a main discharge space, and protruding portions protruding on the base portions, respectively, and which defines stepped spaces on either side of the main discharge space. The stepped spaces are formed according to stepped surfaces formed by the base portions and the protruding portions. The PDP further comprises a pair of a scan electrode and a sustain electrode which generate a mutual discharge through the main discharge space. A channel space is defined by outer walls of the protruding portions on either side of the main discharge space, and an external light absorbing layer covers the channel space.