PROBLEM TO BE SOLVED: To provide a medical treatment instrument in which frictional resistance between an internal surface of a sheath member and a transmission member inserted in the sheath member is surely reduced, a treatment driving force is transmitted to a treatment member from an operation part by low loss, and thereby a smooth treatment can be performed.SOLUTION: The medical treatment instrument comprises: a long and flexible sheath member 15, 19 an operation part located at a base end part opposite to the front end side by which a treatment member of the sheath member is supported and a transmission member 21 which is inserted into the sheath member movably forward and backward and transmits a treatment driving force from the operation part to the treatment member. A coil-shaped retainer member 201 is provided between the inner circumferential surface of an insertion hole of the sheath member, into which the transmission member 21 is inserted, and the transmission member 21.COPYRIGHT: (C)2013,JPO&INPIT【課題】シース部材の内面と、シース部材内に挿通される伝達部材との間の摩擦抵抗を確実に軽減して、操作部から処置機能部材に処置駆動力を低損失で伝達し、円滑な処置が行える医療用処置具を提供する。【解決手段】医療用処置具は、可撓性を有する長尺状のシース部材15,19と、シース部材の処置機能部材が支持される先端側とは反対側の基端部に配置された操作部と、シース部材内に進退自在に挿通され処置機能部材に操作部からの処置駆動力を伝達する伝達部材21とを有する医療用処置具であって、伝達部材21が挿通されるシース部材の挿通孔の内周面と、伝達部材21との間に、コイル状のリテーナ部材201を配置した。【選択図】図16
