PROBLEM TO BE SOLVED: To provide an excessive insertion prevention tool for preventing excessive insertion when an endoscope device is inserted into an endoscope, without applying a stress to an operator who performs operation after insertion of it.SOLUTION: An excessive insertion prevention tool 1 comprises: a first movable fixing part 7 and a second movable fixing part 8 capable of sliding along a sheath part 4 respectively, capable of being fixed to optional positions on the sheath part 4 and releasing the fixing state and a coil spring 9 connecting the first and second movable fixing parts along the sheath part 4, and energizing the second movable fixing part 8 to the first movable fixing part 7 side. The second movable fixing part 8 is formed into a shape for contacting an insertion port 6 and stopping insertion, when the sheath part 4 is inserted into an endoscope 5.SELECTED DRAWING: Figure 1
