A method for manufacturing a rectifier in which a rectifying element (22a,23a), which has a columnar heat sink and is equipped with a semiconductor pellet that converts alternating current to direct current, is press-fitted into a press-fit hole of a heat dissipation heat sink (22,23) by aligning the axis of said rectifying element (22a,23a) with the axis of the press-fit hole, the method including: said heat dissipation heat sink (22,23) which has the press-fit hole whose inner peripheral surface is a cast skin surface; a press-fit head which applies a load to said heat dissipation heat sink (22,23); an insertion guide which has a through hole, retains said rectifying element (22a,23a) by the through hole, and guides said rectifying element (22a,23a) so as to align the axis of said rectifying element (22a,23a) with the axis of the press-fit hole of said facing heat dissipation heat sink (22,23); and a load receiving jig which is formed with a protrusion portion at one end portion thereof, the method comprising the steps of: sandwiching said heat dissipation heat sink (22,23) by said press-fit head and said insertion guide by aligning the axis of said rectifying element (22a,23a) in said insertion guide with the axis of the press-fit hole of said heat dissipation heat sink (22,23) and making said press-fit head face said heat dissipation heat sink (22,23); making the protrusion portion of said load receiving jig face said columnar heat sink of said rectifying element (22a,23a) in the through hole of said insertion guide; and press-fitting said rectifying element (22a,23a) into the press-fit hole of said heat dissipation heat sink (22,23) by pressing the periphery of the press-fit hole of said heat dissipation heat sink (22,23) by said press-fit head and receiving a load applied to said columnar heat sink of said rectifying element (22a, 23a) by the protrusion portion of said load receiving jig wherein said load receiving jig has an annular receiving surface with a concave portion at a central portion at an end portion of the protrusion portion thereof and receives a load applied to an outer peripheral edge portion (27a,27c) of said columnar heat sink of said rectifying element (22a, 23a) by the annular receiving surface. said heat dissipation heat sink (22,23) which has the press-fit hole whose inner peripheral surface is a cast skin surface; a press-fit head which applies a load to said heat dissipation heat sink (22,23); an insertion guide which has a through hole, retains said rectifying element (22a,23a) by the through hole, and guides said rectifying element (22a,23a) so as to align the axis of said rectifying element (22a,23a) with the axis of the press-fit hole of said facing heat dissipation heat sink (22,23); and a load receiving jig which is formed with a protrusion portion at one end portion thereof, sandwiching said heat dissipation heat sink (22,23) by said press-fit head and said insertion guide by aligning the axis of said rectifying element (22a,23a) in said insertion guide with the axis of the press-fit hole of said heat dissipation heat sink (22,23) and making said press-fit head face said heat dissipation heat sink (22,23); making the protrusion portion of said load receiving jig face said columnar heat sink of said rectifying element (22a,23a) in the through hole of said insertion guide; and press-fitting said rectifying element (22a,23a) into the press-fit hole of said heat dissipation heat sink (22,23) by pressing the periphery of the press-fit hole of said heat dissipation heat sink (22,23) by said press-fit head and receiving a load applied to said columnar heat sink of said rectifying element (22a, 23a) by the protrusion portion of said load receiving jig