A method for manufacturing a semiconductor device, comprising: mounting power semiconductor elements on an insulating circuit substrate, and mounting the insulating circuit substrate on a metal base plate; simultaneously with the mounting of the power semiconductor elements and the mounting of the insulating circuit substrate, processing connecting terminals (31a, 31b) into a predetermined shape, and carrying out insert molding of a case together with the connecting terminals (31a, 31b), wherein during the insert molding control terminal insertion holes are formed at a surface of a case bottom portion; mounting the molded case in a position on the metal base plate, in which the case bottom portion surrounds the insulating circuit substrate, the control terminal insertion holes being disposed at the surface of the case bottom portion opposite to the metal base plate; wire connecting the connecting terminals (31a, 31b) and the power semiconductor elements; inserting linearly shaped control terminals into predetermined control terminal insertion holes; inserting the control terminals and the connecting terminals (31a, 31b) into through holes provided in a printed substrate; soldering connections of the printed substrate and the control terminals and connections of the printed substrate and the connecting terminals (31a, 31b) and thereby securing the connection between the printed substrate and each of the control terminals and the connecting terminals (31a, 31b); and injecting an insulating gel into an inner portion of the semiconductor device, and mounting a cover, thereby completing the semiconductor device, wherein the method further comprises: configuring the number of control terminal insertion holes to be larger than the number of the control terminals. mounting power semiconductor elements on an insulating circuit substrate, and mounting the insulating circuit substrate on a metal base plate; simultaneously with the mounting of the power semiconductor elements and the mounting of the insulating circuit substrate, processing connecting terminals (31a, 31b) into a predetermined shape, and carrying out insert molding of a case together with the connecting terminals (31a, 31b), wherein during the insert molding control terminal insertion holes are formed at a surface of a case bottom portion; mounting the molded case in a position on the metal base plate, in which the case bottom portion surrounds the insulating circuit substrate, the control terminal insertion holes being disposed at the surface of the case bottom portion opposite to the metal base plate; wire connecting the connecting terminals (31a, 31b) and the power semiconductor elements; inserting linearly shaped control terminals into predetermined control terminal insertion holes; inserting the control terminals and the connecting terminals (31a, 31b) into through holes provided in a printed substrate; soldering connections of the printed substrate and the control terminals and connections of the printed substrate and the connecting terminals (31a, 31b) and thereby securing the connection between the printed substrate and each of the control terminals and the connecting terminals (31a, 31b); and injecting an insulating gel into an inner portion of the semiconductor device, and mounting a cover, thereby completing the semiconductor device, wherein the method further comprises: configuring the number of control terminal insertion holes to be larger than the number of the control terminals.