INSULATED ELECTRIC WIRE, PRODUCTION METHOD THEREFOR, COIL AND COIL PRODUCTION METHOD USING SAME

There is provided an insulated electric wire formed by covering a rectangular conductor wire having a rectangular cross-sectional shape with an insulating film. The insulating film is formed of an inner layer covering a surface of the rectangular conductor wire, and an outer layer covering a surface of the inner layer. A thickness (t1) of a section of the inner layer, which covers one short side of two facing short sides of the same length of a rectangular cross section of the rectangular conductor wire, is greater than a thickness (t2) (including that t2= 0) of a section of the inner layer which covers the other short side. An elastic modulus and/or a yield stress of the inner layer are less than an elastic modulus and/or a yield stress of the outer layer.