To provide a semiconductor device manufacturing method which can improve manufacturing efficiency by improving a utilization ratio of an ion implanter.

A semiconductor device manufacturing method comprises: forming a through part 20 on a semiconductor substrate 10; performing first ion implantation into the semiconductor substrate 10 via the through part 20; removing the through part at least partially in a thickness direction in at least a part of a region of the through part 20 when viewed from above; and performing second ion implantation IJ2 into the semiconductor substrate 10 in at least a part of region. Implantation energy of the first ion implantation and implantation energy of the second ion implantation are equal to with each other.