To form a cross-linked insulating layer and a cross-linked semiconductive layer without being softened and deformed, by a method wherein, before an inside semiconductive layer is formed on a conductor connection, a process in which an exposed outside semiconductive layer, an exposed insulating layer and the exposed inside semiconductive layer are cross-linked is performed.

An outside semiconductive layer, an insulating layer and an inside semiconductive layer are exposed. After that, a cable whose terminal part is treated is prepared, and a cross-linking process is performed. That is to say, at least the inside semiconductive layer 5a is cross-linked out of the exposed outside semiconductive layer, the exposed insulating layer and the exposed inside semiconductive layer 5a, and a cross-linked exposed part 15 is formed. Preferably, not only the inside semiconductive layer but also the insulating layer and the outside semiconductive layer are cross-linked, and they are cross-linked by a cross-linking operation in which a high-energy beam such as an electron beam or the like is irradiated, or by a chemical cross-linking operation by using a cross-linking agent such as an organic peroxide or the like. In addition, in the case of the chemical cross-linking operation a by-product is generated, and the cable is degraded. A cross-linked part is dried after the cross- linking operation, and the by-product is removed.