Abstract: In a semiconductor device which includes a substrate having a peripheral edge, and a semiconductor integrated circuit fabricated on the substrate so that the circuit has an outer periphery spaced inwardly of the peripheral edge of the substrate, a conductive layer is provided to extend along at least a part of the outer periphery of the circuit and between the outer periphery of the circuit and peripheral edge of the substrate, or the conductive layer is disposed close to metal electrodes provided on the substrate for connection to the integrated circuit, and a potential is applied to the conductive layer and to the substrate to create at the conductive layer a potential barrier maintained at a potential higher than the potential of the substrate.