PROBLEM TO BE SOLVED: To provide a bending operation device of an endoscope capable of reliably maintaining the maximum bending angle of a bending part of the endoscope.SOLUTION: A bending operation device 30 of an endoscope comprises: an engaging member 104 provided in a wire 103 inserted into a bending part and wound around a rotary drum 100 of an operation part； a first facing surface 105 and a second facing surface 106 which face each other in a rotary shaft direction SD along a rotary shaft 101 of the rotary drum； an engaged member 107 slidable in a wire extension direction WD along at least the wire on the first facing surface and engageable with the engaging member； and a regulation member 108 extending from the second facing surface to the first facing surface side, terminating before reaching the first facing surface, and capable of adjusting the extension length from the second facing surface to the first facing surface side. A tapered surface 107a facing the second facing surface side and gradually extending toward the first opposing surface side in the rotary shaft direction as approaching one side in the wire extension direction is formed in the engaged member. The regulation member regulates the movement of the engaged member to one side in the wire extension direction by coming into contact with the tapered surface.SELECTED DRAWING: Figure 3
