Patent ID: 8262558

Claim:
A treatment tool comprising: an inserted part that is to be disposed inside a body, wherein the inserted part can be inserted and passed through an endoscope, wherein a treatment part for carrying out a specific treatment on a tissue is provided to a distal end of said inserted part, wherein the treatment part is configured to freely project and retract in the inserted part; an operator portion attached to a base end portion of said inserted part which is configured to be pulled out from said endoscope, for manipulating the projection and retraction of said treatment part, said operator portion which is provided with an operator portion main body which is fixed to a sheath of said inserted part; and an operator tube which is inserted in a freely advancing and retreating manner into a hole formed in said operator portion main body, and in which a base is provided that communicates with said treatment part; wherein, expanded diameter sections which are formed with said hole of said operator portion main body at two sites along the advancing/retreating direction of said operator tube, a first expanded diameter section on a base end side of said hole being formed corresponding to a position at which said treatment part is housed in said sheath, and a second expanded diameter section on a distal end side of said hole being formed corresponding to a position at which said treatment part is projected out from said sheath; locking parts which undergo deformation in the radial direction of the operator portion main body to engage with said first and second expanded diameter sections, provided to said operator tube; and wherein said locking parts have projecting parts capable of engaging with said first and second expanded diameter sections, said projecting parts which have: an inclined end surface provided on a base end side of said projecting parts, and configured to deform said locking parts in a reduced diameter direction during retraction of said operator tube; and a first inclined surface provided to a position deviated in a circumferential direction of said operator tube with respect to said end surface, and inclined so as to close an axis of said operator tube toward a distal end of said operator tube, and said first expanded diameter section provided on the base end side of said operator portion main body has a surface provided on a based end side of an inner wall of said first expanded diameter section, and inclined so as to close said axis toward a distal end of said operator portion main body, and configured to engage with said first inclined surface.