A method of manufacturing a semiconductor device is disclosed. The semiconductor device includes a semiconductor body of a first conductivity type, a hetero semiconductor region adjacent to one main surface of the semiconductor body and having a band gap different from that of the semiconductor body, and a gate electrode formed in a junction portion between the hetero semiconductor region and the semiconductor body through a gate insulating film. The method includes a first process of forming a predetermined trench by using a mask layer having a predetermined opening on one main surface side of the semiconductor body, a second process of forming a buried region adjacent to at least a side wall of the trench and so as to extend from the trench, a third process of forming a hetero semiconductor layer so as to adjoin the semiconductor body and the buried region, and a fourth process of forming the hetero semiconductor region by patterning the hetero semiconductor layer.