PROBLEM TO BE SOLVED: To smoothly transmit torque from an operation section to a treatment section.SOLUTION: A treatment tool for endoscope comprises: a flexible sheath 2 passed through the inside of a treatment tool guide tube of an endoscope an operation wire 3 inserted into the sheath 2 and a treatment section 6 provided with a pair of treatment pieces 8 which are pivotably supported by a support shaft 12 and are pivotally displaced between an open position and a closed position a connection mechanism which rotatably supports the treatment section 6 and is connected with the sheath 2 and an operation section 7 which is connected to a rear end of the operation wire 3 and to a rear end of the sheath 2, and displaces the treatment pieces 8 between the open position and the closed position by advancing and retracting the operation wire 3. The connection mechanism comprises: a tip support frame 4 having a pair of arms which extends from a toric base end section and has the support shaft 12 pivotally supporting the treatment section and penetrating at the tip of the arms, and provided with a key-shaped section with a toric rear end of the base end section bent inwardly and a receiving frame 20 which protrudes in an outer peripheral direction such that a cylindrically shaped tip engages with the key-shaped section of the tip support frame 4, and which is shaped such that a tip of the sheath 2 fits into an end outer periphery.
