An insulated electric wire, comprising: a conductor; and a covering layer disposed around an outer circumference of the conductor, wherein the covering layer comprises a first flame retardant layer composed of a flame retardant resin composition including a resin component and a second flame retardant layer composed of a flame retardant resin composition including a resin component, and an insulating layer interposed between the first flame retardant layer and the second flame retardant layer, wherein the insulating layer comprises a resin composition including a resin component, and the resin component includes 40% by mass or more of a first resin having a melting point of 125 degrees C or higher of 100% by mass of the resin component and a second resin other than the first resin having the melting point of 125 degrees C or higher, wherein the first resin is composed of polyethylene having a density of 0.930 g/m 3 or more, wherein the second resin is selected from one or two or more kinds of the group consisting of a polyimide, a polyether ether ketone (PEEK), a polyamide imide, a linear low density polyethylene (LLDPE), an ethylene-a olefin copolymer, an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-methyl acrylate copolymer, an ethylene-glycidyl methacrylate copolymer, an ethylene-acrylic acid ester copolymer, and an ethylene-propylene-diene copolymer, wherein the resin component of the flame retardant resin composition of the first flame retardant layer and the resin component of the flame retardant resin composition of the second flame retardant layer are selected from the group consisting of polyolefin, polyimide, polyetheretherketone, and polyamideimide. a conductor; and a covering layer disposed around an outer circumference of the conductor, wherein the covering layer comprises a first flame retardant layer composed of a flame retardant resin composition including a resin component and a second flame retardant layer composed of a flame retardant resin composition including a resin component, and an insulating layer interposed between the first flame retardant layer and the second flame retardant layer, wherein the insulating layer comprises a resin composition including a resin component, and the resin component includes 40% by mass or more of a first resin having a melting point of 125 degrees C or higher of 100% by mass of the resin component and a second resin other than the first resin having the melting point of 125 degrees C or higher, wherein the first resin is composed of polyethylene having a density of 0.930 g/m 3 or more, wherein the second resin is selected from one or two or more kinds of the group consisting of a polyimide, a polyether ether ketone (PEEK), a polyamide imide, a linear low density polyethylene (LLDPE), an ethylene-a olefin copolymer, an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-methyl acrylate copolymer, an ethylene-glycidyl methacrylate copolymer, an ethylene-acrylic acid ester copolymer, and an ethylene-propylene-diene copolymer, wherein the resin component of the flame retardant resin composition of the first flame retardant layer and the resin component of the flame retardant resin composition of the second flame retardant layer are selected from the group consisting of polyolefin, polyimide, polyetheretherketone, and polyamideimide.