Abstract: A method of forming a porous coating layer on a surface of an implant for implantation into the living body is provided. The method includes a first step of providing an implant base body, which is made of a material including a metal component, and a second step of sintering metal powder on a surface of the implant base body using rapid prototyping. In the second step, a laser beam irradiation tool necessary for the rapid prototyping repeatedly moves along a predetermined movement path to sinter the metal powder, which is sprayed along the predetermined movement path, on the surface of the implant base body, and an inflection point is present between semicircular curved section paths in the predetermined movement path.