medical treatment tool (1) is at least partially formed of a bending operation can be curved portion (32), the insertion portion to be inserted into the patient and (3), the curved portion (32) provided on the outer periphery, with enhanced body and (5) that extends in the radial direction of the curved part (32), said expandable body (5), the axial direction of the distal end portion of the expandable body (5) (51) is fixed to the insertion part (3), are movable in the axial direction with respect to the insertion portion proximal end portion (52) (3).医療用処置具(1)は、少なくとも一部が湾曲操作可能な湾曲部(32)で構成され、患者の体内に挿入される挿入部(3)と、前記湾曲部(32)の外周に設けられ、当該湾曲部(32)の径方向に拡張する拡張体(5)とを備え、前記拡張体(5)は、当該拡張体(5)の軸方向の先端部(51)が前記挿入部(3)に固定され、基端部(52)が前記挿入部(3)に対して前記軸方向に移動自在に設けられている。
