Abstract: A method of manufacturing a metal core for a resin gear is provided. The metal core has a boss portion into which a shaft is press-fitted and a ring portion to which an outer peripheral resin is joined. The method includes swaging a plate material having a center hole by pressing the plate material in an axial direction to form a swaged body, and forging the swaged body by pressing the swaged body in the axial direction under a higher pressure. The swaging includes deforming a portion around the center hole in the axial direction to form an inner circumferential swaged portion, and deforming an outer circumferential portion of the plate material in the same axial direction to form an outer circumferential swaged portion. The forging includes forming the inner circumferential swaged portion into the boss portion, and forming the outer circumferential swaged portion into the ring portion.