Abstract: In connecting a conductor consisting of a plurality of core lines of an electric wire to a terminal, it is performed to make the core lines, which are adjacent to each other at a peripheral part in a vicinity of an end of the conductor, into contact with each other adhesively and join the end of the conductor to the terminal by pressurized ultrasonic oscillation using a compression-and-vibration horn. In making the adjacent core lines in contact with each other, a metal sleeve may be fitted in an annular manner in the vicinity of the end or the peripheral part of the conductor may be subjected to welding, alternatively.

Abstract: A structure of an electric wire for connection includes a conductor end portion of the electric wire comprised of a plurality of core wires. The conductor end portion is compressed by press-forming to pressurize from the side of an outer peripheral surface thereof toward the side of the axis thereof. A tapered surface is formed by the press-forming on the outer peripheral surface of at least a tip side of the conductor end portion, which inclines toward a direction crossing an axial direction of the conductor end portion. The conductor end portion on which the tapered surface is formed is electrically connected with a connected portion by ultrasonic joining.