Provided is a surgical operating apparatus for an endoscope capable of changing the size of an image of an observation target part reflected in an endoscopic image obtained by an endoscope and the size of a range of an observation target part so that an operator can desire. The mantle tube for guiding the endoscope 100 and the treatment instrument 200 into the body cavity includes a slider 400 which is an interlocking member for advancing and retracting the endoscope 100 and the treatment instrument 200 in conjunction with each other. In the slider 400, the other operates in conjunction with the dead zone in which the other does not interlock with the advancing and retracting movement of either one of the endoscope 100 and the treatment instrument 200 and the other in association with the advancing and retreating movement of either the endoscope or the treatment instrument And a sensuous zone region. The image processing unit 152 (zoom means) of the processor unit 108 changes the zoom magnification of the endoscopic image from the endoscope 100 by electronic zoom based on the operation of the foot switch 156. On the other hand, in the dead zone region of the slider 400, the zoom operation by the foot switch 156 is switched between valid and invalid according to the relative position of the distal end of the endoscope 100 to the distal end of the treatment instrument 200.内視鏡により得られる内視鏡画像に映り込む観察対象部位の画像の大きさや観察対象部位の範囲の大きさを術者が望むように変更できる内視鏡用外科手術装置を提供する。内視鏡100及び処置具200を体腔内に案内する外套管は、内視鏡100と処置具200とを連動させて進退移動させる連動部材であるスライダ400を備える。スライダ400は、内視鏡100及び処置具200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。プロセッサ装置108の画像処理部152(ズーム手段)は、内視鏡100からの内視鏡画像のズーム倍率をフットスイッチ156の操作に基づき電子ズームにより変更する。一方、スライダ400の不感帯領域では、処置具200の先端に対する内視鏡100の先端の相対位置に応じてフットスイッチ156によるズーム操作の有効及び無効が切り替えられる。
