Provided are an outer tube and an endoscopic surgical apparatus capable of selectively switching between a state in which a tubular member (a mantle tube or the like) can be rotated around an axial direction and a state in which the tubular member (such as an outer tube) cannot rotate. An outer port 500 to which the present invention is applied is an outer tube that is sheathed by a mantle tube 300 inserted into a body wall and prevents rotation and forward / backward movement with respect to the body wall. Provided in the outer port 560, an insertion portion 540 (inner cylinder 552) having a portion, a head portion 560 that is rotatably connected to a proximal end portion of the inner cylinder 552, and has a proximal end opening portion into which the outer port 560 is introduced. The pressure contact member 576 for restricting the rotation of the outer tube 300, the inner cylinder 552, and the head portion 560 are arranged between the inner tube 552 and the base portion of the inner tube 552. A spring member 578 that is deformable between a rotation-locked state in which rotation is restricted and a rotation-unlocked state in which the head portion 560 can be rotated with respect to the inner cylinder 552 by disengagement； 560 to rotatably provided, comprising a, a rotary operating member 590 to deform the spring member 578 between the rotary unlocked condition and rotation lock state.管状部材（外套管等）を軸方向周りに回転可能な状態と回転不能な状態とを簡単な操作で選択的に切り替えることが可能な外装管及び内視鏡用外科手術装置を提供する。本発明が適用されるアウターポート５００は、体壁に刺入される外套管３００に外装され、体壁に対する回転や進退移動を防止する外装管であって、外套管３００が導出される先端開口部を有する挿入部５４０（内筒５５２）と、内筒５５２の基端部に回転自在に連結され、アウターポート５６０が導入される基端開口部を有するヘッド部５６０と、アウターポート５６０に設けられ、外套管３００の回転を規制する圧接部材５７６と、内筒５５２とヘッド部５６０との間に配置され、内筒５５２の基端部に係合することによって内筒５５２に対するヘッド部５６０の回転が規制された回転ロック状態と、係合が解除されて内筒５５２に対するヘッド部５６０の回転が可能な回転アンロック状態との間で変形可能なバネ部材５７８と、ヘッド部５６０に回動自在に設けられ、回転ロック状態と回転アンロック状態との間でバネ部材５７８を変形させる回転操作部材５９０と、を備える。
