To fix an operation wire to a bend piece while preventing bonding peeling and deformation around a bonded part.

Of the bend pieces 20 configuring a bend part 18, the bend piece 20 at the chip is provided with two projection pieces 60 so as to be projected from the end part on the proximal end side of a cylindrical part 26 to the inner side in the radial direction. At the center of the projection piece 60, an insertion hole 61 is formed. To the insertion hole 61, one end of a right and left operation wire 38 is inserted. The end part of the right and left operation wire 38 inserted to the insertion hole 61 is fixed inside the bend piece 20 by solder 62. The solder 62 is put on so as to cover the entire end part of the right and left operation wire 38 and come into contact with two surfaces which are the inner peripheral surface 26a of the cylindrical part 26 and the inner side face 60a of the projection piece 60.