To provide a metal wire and an electric wire of high mechanical strength and high ductibility that have sufficiently increased ductibility as well as sufficiently increased mechanical strength. A metal wire manufactured at least by being subjected to an extension in which a metal wire is extended in an axial direction, and having a hardness distribution in which hardness decreases toward a specific peripheral portion from a central portion in a cross-section orthogonal to axis, whereby a softened peripheral portion becomes to show a good malleability as well as a high resistance to cracking, so as to attain an improvement of mechanical strength and ductibility.