Abstract: A plurality of shielded core wires has a first diameter. A conductive cover member covers the shielded core wires. A first insulating sheath covers the conductive cover member. A pair of resin members, each formed with a groove having a semi-ellipsoidal shape are thermally integrated with each other for forming an ellipsoidal through hole while accommodating the first insulating sheath therein. A major axis length of a cross section of the ellipsoidal through hole is substantially identical with a length obtained by adding each first diameter, twice a thickness of the conductive cover member and twice a thickness of the first insulating sheath. A minor axis length of a cross section of the ellipsoidal through hole is substantially identical with by adding the first diameter, twice the thickness of the conductive cover member and twice the thickness of the first insulating sheath.