To provide a sheath for washing an endoscope, having enough length to remove deposit, and preventing a hindrance to endoscopic observation in ordinary observation or treatment.

In this sheath for washing an endoscope, a sheath tip part where a blade 71 for removing deposit is disposed at the distal end of a sheath insert part, and a wire connecting member for connecting a pair of driving wires 72 for moving the blade 71 and a slidable operating wire is disposed between the sheath tip part and a tip cover part 60. The sheath tip part includes a blade abut part 52e projected and located outside of the paired driving wires 72 and abutting on the blade 71 during the movement caused by movement of the driving wires 72, and a projecting part 52 having a blade holding surface for holding the side of the blade 71 deformed with the movement of the driving wires 72 in a curved shape after abutting on a wire disposition groove 52c where the wiring wires 72 are slidably disposed and the blade abutting part 52e.