To provide a treatment device for an endoscope equipped with a double tube which is easy to operate and can be manufactured less expensively.SOLUTION: A treatment device for an endoscope includes a double tube inserted through a channel of the endoscope. The double tube is provided with: an outer tube； and an inner tube which is inserted through the outer tube and relatively moves forward and backward with respect to the outer tube. The outer tube of the double tube is formed by a plastic material where silicon compound is added to an organic polymer, so that when the inner tube moves forward and backward with respect to the outer tube in the state that the double tube is bent along a channel path, frictional resistance between an outer peripheral surface to be a sliding surface of the inner tube and an inner peripheral surface to be a sliding surface of the outer tube is smaller than when both the outer tube and the inner tube of the double tube are formed only by the organic polymer.SELECTED DRAWING: Figure 1【課題】操作がし易く安価で製造することができる二重チューブを備えた内視鏡用施術器具を提供する。【解決手段】内視鏡のチャネルを通じて挿入される二重チューブを備え、二重チューブは、外側チューブと、外側チューブを通じて挿入され、外側チューブに対して相対的に前進及び後退する内側チューブとを備え、二重チューブの外側チューブは有機高分子にシリコン化合物を追加したプラスチック材料から形成されることにより、チャネルの経路に沿って二重チューブを曲げた状態で外側チューブに対して内側チューブを前進及び後退させるとき、内側チューブの摺動面である外周面と外側チューブの摺動面である内周面間の摩擦抵抗が、二重チューブの外側チューブと内側チューブの両者を有機高分子だけから形成した場合より小さい。【選択図】図１
