PROBLEM TO BE SOLVED: To provide an attachment/detachment mechanism for an internal insertion member and an overcoat member, which enables reliable fixation to be performed with respect to a twisting direction (rotational direction) and a pull-out direction, and an operation tool system.SOLUTION: An attachment/detachment mechanism for detachably fixing an operation tool 2 and an overcoat member 4 is configured as follows. That is, the overcoat member 4 includes a first overcoat member 41 that has an engagement part 41-2 configured to come into contact with an engagement member 2-1, and a second overcoat member 42 that is arranged between the first overcoat member 41 and the operation tool 2 and that has a hole part 42-2.COPYRIGHT: (C)2015,JPO&INPIT【課題】内挿部材と外套部材との着脱機構であって、捻り方向(回転方向)と引き抜き方向とについて確実に固定することが可能な着脱機構及び術具システムを提供すること。【解決手段】術具2と外套部材4とを着脱可能に固定する着脱機構を次のように構成する。すなわち、前記外套部材4は、係合部材2-1に接触するように構成された係合部41-2を有する第1外套部材41と、第1外套部材41と術具2の間に配置され、孔部42-2を有する第2外套部材42とを有する。【選択図】図7
