PROBLEM TO BE SOLVED: To provide a treatment tool for an endoscope capable of reliably accessing a target position in the nose such as a paranasal cavity.SOLUTION: A treatment tool for an endoscope has a guide pipe and a guide sheath. The guide pipe allows an insertion part to be inserted therein such that the tip side of a tip of the insertion part and the tip side of a first tip are observable through the first tip by using an observation optical system of the endoscope, or the tip side of the tip of the insertion part is observable by using the observation optical system in a state in which the tip of the insertion part protrudes from the first tip. The guide sheath has an inner diameter which allows the insertion part to be inserted therein such that the tip of the insertion part is protrudable from a second tip thereof, and is inserted into the guide pipe such that the second tip of the guide pipe is protrudable from the first tip.SELECTED DRAWING: Figure 14【課題】 鼻の、例えば副鼻腔など、目的の位置に確実にアクセス可能な内視鏡用処置具を提供する。【解決手段】 内視鏡用処置具はガイドパイプとガイドシースとを有する。ガイドパイプは、その第１先端を通して内視鏡の観察光学系で挿入部の先端の先端側かつ第１先端の先端側を観察可能、又は、挿入部の先端を第１先端に対して突出させた状態で挿入部の先端の先端側を観察光学系で観察可能に挿入部をその内側に挿通させる。ガイドシースは、挿入部の先端をその第２先端に対して突出可能に挿入部をその内側に挿通させる内径を有し、ガイドパイプの第１先端に対して第２先端を突出可能にガイドパイプの内側に挿通される。【選択図】図１４
