Abstract: The present invention relates to an electric wire having a conductor and a covering layer covering the conductor. The electric wire is inserted under pressure between two contact portions of a terminal of an insulation displacement connector to electrically connect to the terminal. In the present invention, the covering layer is made of a covering material obtained by irradiating with ionizing radiation a resin composition containing an ethylene copolymer and a metal hydroxide surface-treated with a predetermined silane compound. The 100% tensile modulus of the covering material is 7.8 MPa or more. The 100% tensile modulus and elongation satisfy E1>270−8.5×10−6×Y (where E1 is the elongation and Y is the 100% tensile modulus).