There is provided a wiring material including a core layer made of metal and a clad layer made of metal and a fiber in which the core layer is copper or an alloy containing copper and the clad layer is formed of copper or the alloy containing copper and the fiber having a thermal expansion coefficient lower than that of copper, the wiring material having a stacked structure in which at least one surface of the core layer is closely adhered to the clad layer, and the fiber in the clad layer is arranged so as to be parallel to the surface of the core layer.