To reduce labor and time required for connection of armoring steel wires and apply tensile force to armoring steel wires of a connection part.

First steel wire fixation metal fittings 5A and second steel wire fixation metal fittings 5B which are divided into plural pieces in a circumferential direction are used. In the first steel wire fixation metal fitting 5A, grooves 7A in which an end of an armoring steel wire 2A of one cable is fixed to an end on one end side are formed, and a tapered surface 8A is formed on the outer peripheral surface so that the outer diameter becomes larger from the one end side toward the other end side. In the second steel wire fixation metal fitting 5B, grooves 7B in which an end of an armoring steel wire 2B of another cable is fixed to an end on the other end side are formed, and a tapered surface 8B is formed on the inner peripheral surface so that the inner diameter becomes smaller from the other end side toward the one end side. A bolt 6 is screwed in a direction in which the second steel wire fixation metal fitting 5B is pressed against the first steel wire fixation metal fitting 5A, and both of the steel wire fixation metal fittings are connected by sliding them in mutually opposite directions along the tapered surfaces, thereby applying tensile force to the armoring steel wires 2A, 2B.