Method of forming porous coating layer on surface of implant for implantation into living body

A method of forming a porous coating layer on a surface of an implant for implantation into a living body, the method comprising:

• 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,
• wherein, 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 so that the porous coating layer is formed on the surface of the implant base body,
• the predetermined movement path includes a semicircular first curved section path and a semicircular second curved section path,
• an inflection point is present between the first curved section path and the second curved section path, and
• in a process in which the movement path of the laser beam irradiation tool is changed from the first curved section path to the second curved section path, the first curved section path and the second curved section path reduce a decrease in a movement speed of the laser beam irradiation tool to reduce a difference in energy yield per unit area of the surface, which is due to a laser beam irradiated by the laser beam irradiation tool, so that a decrease in a porosity of the porous coating layer formed on the surface of the implant base body is prevented.