The invention provides a semiconductor device, which makes two high-voltage transverse devices with approximate terminal voltage arranged on surface adjacent areas. The two devices both have areas which are opposite to the conducting type of a substrate and are closely attached with the substrate; an isolating area is arranged between areas with different voltage; an effective value of dielectricflux density, which is transmitted to the substrate when a semiconductor area in the isolating area is totally exhausted, is between effective values of dielectric flux density of voltage-proof areasof the two devices on two sides of the isolating area; and two sides in the isolating area are at least provided with areas opposite to the conduction type of the substrate. The semiconductor device provided by the invention is also used for manufacturing low side high voltage nMOST with approximate terminal voltage and a high voltage nMOST device M1 used in a high-voltage level displacement circuit on the surface adjacent areas.