A semiconductor device has a high voltage circuit section disposed on a semiconductor substrate having a first conductivity. The high voltage circuit section has a well region with a second conductivity, a first heavily doped impurity region with the first conductivity and disposed on the well region, a second heavily doped impurity region having a second conductivity and disposed on the semiconductor substrate, a trench isolation region disposed between the first and second heavily doped impurity regions, and an interconnect disposed over the trench isolation region. First and second electrodes are disposed above the trench isolation region, below the interconnect, and on opposite sides of a junction between the well region and the semiconductor substrate. The first electrode is disposed above the semiconductor substrate, and the second electrode is disposed above the well region. The first and second electrodes prevent parasitic formation of an inverse layer on a surface of the semiconductor substrate due to a potential of the interconnect.