A method for manufacturing a power semiconductor device includes forming a trench in a semiconductor substrate, forming a gate insulation film and a gate electrode in the trench, implanting a first conductivity type impurity into the semiconductor substrate to form a first conductivity type body region, implanting a second conductivity type impurity onto a surface of the semiconductor substrate to form a second conductivity type source region, forming an interlayer insulation film in the trench, implanting the first conductivity type impurity onto the surface of the semiconductor substrate to form a first conductivity type highly doped body contact region, exposing a portion of a side surface of the trench, and forming a source metal to be in contact with the exposed side surface of the trench.