Disclosed is a stage system that includes a stage for supporting and moving a substrate, and a probe for measuring a potential of a substrate without contact thereto, the probe being supported by the stage so as to be opposed to one of a bottom face and a side face of the substrate. Also disclosed is a stage system that includes a substrate holding member for holding a substrate, the substrate holding member having a protrusion and a first electrode, the first electrode being provided inside the substrate holding member and adjacent said protrusion, a terminal for adjusting a potential of said first electrode, and a stage for supporting and moving the substrate holding member through the terminal. Further, a substrate holding system is disclosed, that includes a plurality of protrusions to be supported by a stage, and a plurality of first electrodes disposed adjacent the plurality of protrusions, respectively, and for electrostatically attracting the stage.