PROBLEM TO BE SOLVED: To secure slidability of a bendable wire and a wire guide member in which the bendable wire is inserted, without causing diameter enlargement of a bending section.SOLUTION: A radial position of a guide sheath 45 is regulated by a distance from a center (a central axis S1) of a bending piece to an inner peripheral surface of a connection piece mouthpiece part, and a distance from the center (the central axis S1) of the bending piece to the inner peripheral surface of the connecting mouthpiece, and the distances are set to a distance c or less from the center of the bending piece to a vertex of a head part 34a in the inner diameter side of a rivet 34. This configuration can prevent the guide sheath 45 from coming into contact with the rivet 34 and from being bent, in a bending operation, and can secure slidability of a wire 40 with respect to the guide sheath 45 without causing diameter enlargement of the bending section. Further, the slidability of the wire 40 is secured so as to improve durability of the wire 40 and prevent an increase in wire traction force (bending force).
