An insulated wire according to one embodiment of the present invention is provided with a conductor and an insulating layer arranged on the outer circumference of the conductor. The insulating layer has a multilayer structure including an inner layer and an outer layer. The inner layer is formed of an inner layer material containing a silane-grafted chlorine-based polymer (A) that is obtained by graft copolymerizing a silane compound to a chlorine-based polymer (a); and the outer layer is formed of an outer layer material containing a silane-grafted chlorinated polyethylene (B) that is obtained by graft copolymerizing a silane compound to a chlorinated polyethylene (b) and a silane-grafted polyethylene (C) that is obtained by graft copolymerizing a silane compound to a polyethylene (c). The inner layer and the outer layer are configured to be integrally silane crosslinked.