A substrate processing system capable of setting a stable reference ground level for electrical components while handling electrostatic discharge (ESD) is provided. The substrate processing system includes a first ground bar connected to a building ground; and a second ground bar connected to the building ground and physically separated from the first ground bar, wherein the first ground bar is connected to a first electrical component to set a ground level of the first electrical component, wherein the second ground bar is dedicated to a charged component, and the second ground bar is connected to the first charged component to set a path of the electrostatic discharge current generated by the first charged component.