A semiconductor lateral voltage-sustaining region and devices based thereupon. The voltage-sustaining region is made by using the Metal-Insulator-Semiconductor capacitance formed by terrace field plate to emit or to absorb electric flux on the semiconductor surface, so that the effective electric flux density emitted from the semiconductor surface to the substrate approaches approximately the optimum distribution, and a highest breakdown voltage can be achieved within a smallest distance on the surface. The field plate(s) can be either connected to an electrode or floating ones, or connected to floating field limiting rings. Coupling capacitance between different plates can also be used to change the flux distribution.