Endoscopic treatment tool

An endoscopic treatment tool, comprising:

• a tubular sheath;
• an operation portion directly connected to a proximal end of the sheath, the operation portion configured to allow an operation wire inserted through the sheath to slide with respect to the sheath;
• and
• an opening/closing portion constituted by an elastic body having a pair of arm portions attached at a distal end of the operation wire and arranged so as to open each other in a substantially V shape toward a tip of the pair of arm portions,
• the opening/closing portion protrudes from the distal end of the sheath to open the pair of arm portions by an elasticity of the pair of arm portions by sliding the sheath towards a proximal side with respect to the operation wire,
• the opening/closing portion is buried in the distal end of the sheath to close the pair of arm portions by sliding the sheath distally with respect to the operation wire, wherein
• the opening/closing portion has a pair of claw portions at the tip of each of the pair of arm portions that are bent in a closing direction and that can pull a clip connected to a loop member into the sheath by holding a part of the clip during a movement to bury the opening/closing portion in the sheath,
• a gap at a closest portion between the pair of claw portions when the pair of arm portions are buried in the sheath and closed, wherein the gap has a specified value that prevents the loop member from passing through, when a part of the loop member is clipped between the pair of claw portions,
• a first claw portion of the opening/closing portion, which is the claw portion of one arm portion of the pair of arm portions, is bent from a base end by a predetermined radius of curvature,
• a second claw portion of the opening/closing portion, which is the claw portion of the other arm portion, is bent from a base end portion by a radius of curvature longer than the first claw portion and larger than the predetermined radius of curvature,
• the pair of arm portions are closed in such a manner that the second claw portion covers the first claw portion from the outside while in a state of being buried in the sheath such that a distal-most portion of the second claw portion extends past a distal-most portion of the first claw portion,
• the closest portion is formed between a protruding end portion of the first claw portion and the region between a protruding end portion of the second claw portion and the base end portion.