An insulated wire having a conductor, a foamed insulating layer containing a thermosetting resin having cells, coated directly or indirectly onto the outer periphery of the conductor and an outer insulating layer containing a thermoplastic resin having a melting point of 240° C. or higher when the thermoplastic resin is a crystalline resin or a thermoplastic resin having a glass transition temperature of 240° C. or higher when the thermoplastic resin is a non-crystalline resin; electrical equipment using the insulated wire; and a method of producing the insulated wire, containing a step of forming a foamed insulating layer by applying a varnish for forming the foamed insulating layer on the outer periphery of a conductor, by generating foams during baking and a step of forming an outer insulating layer by extrusion-molding a thermoplastic resin composition for forming the outer insulating layer on the outer periphery of the foamed insulating layer.