Abstract: A semiconductor integrated circuit device according to the present invention has a field plate disposed between the element isolation region which surrounds a semiconductor active element and an electrode wiring which is disposed to traverse the element isolation region while being electrically connected with the semiconductor active element, and a predetermined voltage is applied to the field plate. Accordingly, a concentration of the electric field is relieved not only at the boundary region between the element isolating region and the surface of the semiconductor active element which the electrode wiring traverses, but also at the surface of the semiconductor active element under the edge of the field plate, which eventually makes it possible to raise the breakdown-voltage of the semiconductor integrated circuit device.