Disclosed herein is a processing system that can supply a material gas produced inside a material reservoir tank into a processing apparatus while generating almost no pressure loss. The processing system has a processing apparatus including a gas injection injector for injecting a specific material gas into a processing vessel in order to provide specific processing to an object to be processed W, the material gas being produced from a metallic compound material M with low vapor pressure; and a gas supply system for supplying the specific material gas to the gas injector, the gas injector is a shower head portion and the gas supply system provides: a gas passage extending upwardly from the showerhead portion; a material reservoir tank attached to the upper-end portion of the gas passage for containing the metallic compound material therein; and an open/close valve for opening/closing the gas passage.