And manufacturing method thereof power semiconductor device and a power module

In a power semiconductor device for switching at high speed, by the displacement current flowing during switching, and combined high voltage generator and the resistance of the flow path, by the voltage, the thin insulating layer such as a gate insulating film dielectric breakdown , there are cases where the semiconductor device is broken. In the semiconductor device according to the present invention separates the p-type well region arranged in the outer peripheral portion of the power semiconductor device on the inside and two outer, inner inner periphery of the well region on the outside of the well region since there is provided a large field oxide film having a thickness of the gate insulating film up to the, possible to prevent the gate insulating film is the dielectric breakdown by a voltage generated by the displacement current flows when the switching.