A conductor including multiple aluminum-based core wires, and an insulating resin covering directly covering the conductor such that the insulating resin covering is in contact with the aluminum-based core wires. The aluminum-based core wires includes one aluminum-based core wire containing not less than 99 mass % of aluminum in a center of the conductor and aluminum-based core wires positioned concentrically from the center of the conductor, and the conductor is constructed by concentrically twisting 19 or 37 of the aluminum-based core wires in a non-compressed state and at a same pitch such that a thickness deviation of the insulating resin covering is not less than 70%.