To provide a solid phase welding method and a solid phase welding apparatus which are possible to accurately control the welding temperature, to lower the welding temperature and to achieve a solid phase welding of the metallic materials. The present invention provides a solid phase welding method for metallic materials comprising, a first step of forming an interface to be welded by abutting end portions of one material to be welded and the other material to be welded and applying a pressure in a direction substantially perpendicular to the interface to be welded, a second step of raising a temperature of the vicinity of the interface to be welded to a welding temperature by an external heating means, wherein the pressure is set to equal to or more than the yield strength of the one material to be welded and/or the other material to be welded at the welding temperature.