An integrated member can comprise different members each formed of materials having different mechanical characteristics. A method for manufacturing such an integrated member can comprise an electric resistance welding step in which the first member is press-fit into the second member and the press-fit portion can be electrically energized to achieve the electric resistance welding so as to integrate the first member and the second member. The method can further comprise a carburized layer forming step in which carburizing-quenching and tempering, or carbonitriding-quenching and tempering, is performed on the integrated member obtained in the electric resistance welding step to form carburized layers therein in accordance with the mechanical characteristics of the first member and the second member.