A method for manufacturing a semiconductor device, including forming a Fin structure on a semiconductor silicon substrate, performing ion implantation into the Fin structure, and subsequently performing recovery heat treatment on the semiconductor silicon substrate to recrystallize silicon of the Fin structure, wherein the Fin structure is processed so as not to have an end face of a {111} plane of the semiconductor silicon onto a sidewall of the Fin structure to be formed. It also includes a method for manufacturing a semiconductor device that is capable of preventing a defect from being introduced into a Fin structure when the Fin structure is subjected to ion implantation and recovery heat treatment.