To provide a method for manufacturing a nut, by which the nut can be manufactured from a metallic material having a thickness thinner than the length of a female screw, and can suppress an unnecessary waste of a material.

The method for manufacturing the nut comprises thickness increasing steps (a) to (c) for increasing the thickness of a metallic material 10 around a through-hole 11 formed therein by enlarging the diameter of the through-hole 11 by press work, and a female screw forming step for forming a female screw on the inside peripheral surface of the through-hole 11 enlarged in the thickness increasing steps. In the thickness increasing steps, the outside peripheral surface of the metallic material 10 is bound by means of a press die so as not to deform the outside peripheral shape of the metallic material 10. Further, in the thickness increasing steps, the portion around the through-hole 11 in one surface (a punch side surface 13) of the metallic material 10 is heaved by press work, and the other surface (a die side surface 12) of the metallic material 10 is restrained by means of the press die so as to become a flat surface.