A substrate processing system installed on a floor face is provided. The substrate processing system includes a substrate transfer module, a supporting table including a top plate disposed separately from the floor face, a plurality of substrate processing modules disposed on the top plate and coupled to the substrate transfer module along a lateral side of the substrate transfer module, and a plurality of power units disposed below the top plate. Further, the plurality of power units correspond to the plurality of substrate processing modules, respectively, and each of the power units is configured to supply electric power to the corresponding processing module.