A shower head is provided in a processing chamber for processing a substrate therein. Further, the shower head has a facing surface facing a mounting table for mounting thereon the substrate and serves to supply one or more gases through the facing surface toward the substrate. The shower head includes a central gas supply unit for supplying a first gas through a central portion of the facing surface toward the substrate, a peripheral gas supply unit for supplying a second gas through a peripheral portion of the facing surface toward the substrate and a gas exhaust unit, provided with a plurality of gas exhaust holes formed between the central gas supply unit and the peripheral gas supply unit, for exhausting the first and the second gas from the facing surface.