An object of the present invention is to provide an endoscopic surgery device and an outer tube, capable of easily obtaining an image desired by an operator to facilitate treatment as well as of performing minimally invasive surgery. In the endoscopic surgery device and the outer tube, an endoscope and a treatment tool are inserted into a body cavity through an outer tube. The outer tube is provided with a built-in slider. The slider is provided so as to be axially movable in the outer tube body. The endoscope and the treatment tool, inserted into the outer tube, are held by the slider. Moving the treatment tool allows endoscope to be moved in conjunction with the movement of the treatment tool.