A rotation shaft, a bending operation knob, a fixed shaft, two movable disks, a fixed disk, a cam member, a resistance giving member and a fixing lever are included. The resistance giving member has a rocking portion that fixes a rotation position of the cam member in a second position of the movable disks by abutting onto an inner circumferential face of a protruding portion provided at the cam member that moves with rotation of the cam member with an urging force, and is rockable in a diameter direction of the cam member.
