An endoscopic surgical operation apparatus which can easily obtain an image desired by a surgeon and has high operability is provided. The mantle tube is provided with a slider inside the mantle tube main body for guiding the endoscope and the treatment instrument in the body cavity. The slider is provided with a dead zone region in which the endoscope coupling portion and the treatment instrument coupling portion are provided and the other does not interlock with the advancing and retracting movement of either the endoscope or the treatment tool and either the endoscope or the treatment instrument And a sensitive zone region in which the other moves in conjunction with one reciprocating movement. On the proximal end surface of the mantle tube, an air supply connector is formed in which the axial direction is formed parallel to the longitudinal axis of the mantle tube and an air supply tube for detachably connecting an air supply tube for feeding the fluid into the body cavity through the internal space of the mantle tube For example.術者が望む画像を簡単に得られ、操作性の高い内視鏡下外科手術装置を提供する。外套管は、体腔内に内視鏡及び処置具を案内する外套管本体の内部にスライダを備える。スライダには内視鏡連結部及び処置具連結部が設けられ、内視鏡及び処置具のいずれか一方の進退移動に対して他方が連動しない不感帯領域と、内視鏡及び処置具のいずれか一方の進退移動に対して他方が連動する感帯領域とを有する。外套管の基端面には、軸方向が外套管の長手軸と平行に形成され、外套管の内部空間を通じて体腔内に流体を送り込むための送気チューブが着脱自在に接続される送気コネクタが設けられる。
