The trench type semiconductor device includes a gate insulating film placed on the bottom surface and the sidewall surface of the trench formed from the surface of a first base layer; a gate electrode placed on the gate insulating film and fills up into a trench; an interlayer insulating film covering the gate electrode; a second base layer placed on the surface of the first base layer, and is formed more shallowly than the bottom surface of the trench; a source layer placed on the surface of the second base layer; a source electrode connected to the second base layer in the bottom surface of a self-aligned contact trench formed in the second base layer by applying the interlayer insulating film as a mask, and is connected to the source layer in the sidewall surface; a drain layer placed at the back side of the first base layer; and a drain electrode placed at the drain layer, for achieving the minute structure by the self-alignment, reducing the on resistance, and improving the breakdown capability, and providing a fabrication method for the same.