The present invention provides a method for manufacturing a metal material. The method comprises a temperature increasing step of increasing the temperature of a silver material having undergone final plastic working to 700° C. or more and less than a melting point of the silver material in a vacuum or a helium gas atmosphere, a heating step of maintaining the silver material at 700° C. or more and less than the melting point, and a cooling step of cooling the silver material to room temperature in a vacuum or a helium gas atmosphere. For a part of the period of the heating step, the silver material is heated in a mixed atmosphere in which hydrogen gas is mixed with helium gas.