To solve the problem, wherein in a power MOSFET formed in a conventional semiconductor device, it has been difficult to make the FET element finer than the conventional ones, while intending to improve the breakdown voltage thereof.

A semiconductor device has a first conductivity-type drift region formed on a first conductivity-type semiconductor substrate, a second conductivity-type base region formed in the predetermined region of the surface of the drift region, a first conductivity-type source region formed in the predetermined region of the surface of the base region, a contact hole reaching the base region from the side of the surface of the source region, a second conductivity-type column region, formed in the drift region present under the contact hole, a plug made of a first conductive material and embedded in the contact hole, and a wiring made of a second conductive material and connected electrically with the plug.