PROBLEM TO BE SOLVED: To provide a surgical tool which can easily improve the accuracy of external force estimation. SOLUTION: A driven portion 31 to which a driving force is transmitted, a cord-shaped body 35 for transmitting the movement of the driven portion 31 to an operating portion, and a cord-shaped body 35 extending from the driven portion 31 to the operating portion are circumferential. A rotating body 41 wound around a surface, a pair of supporting portions 21 and 22 that support the rotating body 41 so as to be close to and separated from at least one of a driven portion 31 and an operating portion, and one end of itself. A rotary shaft portion 46 that can be fixed to one of a pair of support portions 21 and 22 and rotatably supports the rotating body 41 around the rotation axis, the other end portion of the rotation shaft portion 46, and , A fixed portion arranged between the other of the pair of support portions 21 and 22 so that the relative position with the rotating shaft portion 46 can be changed in the direction of the rotation axis and can be fixed to the other support portions 21 and 22. 51 and are provided. [Selection diagram] Fig. 5【課題】外力推定の精度を高めやすい術具を提供する。【解決手段】駆動力が伝達される被駆動部３１と、被駆動部３１の動きを動作部へ伝達する索状体３５と、被駆動部３１から動作部へ延びる索状体３５が円周面に巻回される回転体４１と、回転体４１を被駆動部３１および動作部の少なくとも一方に対して接近離間可能に支持する一対の支持部２１，２２と、自身の一方の端部が一対の支持部２１，２２の一方に固定可能とされるものであって、回転体４１を回転軸線まわりに回転可能に支持する回転軸部４６と、回転軸部４６の他方の端部、および、一対の支持部２１，２２の他方の間に配置され、回転軸部４６との相対位置が回転軸線方向に変更可能であるとともに、他方の支持部２１，２２に固定可能とされた固定部５１と、が設けられていることを特徴とする。【選択図】図５
