Provided is a surgical apparatus for transanal endoscopic microsurgery (TEM) in which a thin and long endoscope and surgical instruments are inserted through a natural orifice of a human body and the endoscope and surgical instruments are conveyed to the operation area in the body to perform the operation area in the body. According to the surgical apparatus for TEM, a rotation function is added to a barrel of the surgical apparatus for TEM to enable manual rotation of the barrel to a required extent and adjustment of an operation area, without separation of the surgical apparatus for TEM from a fixing frame during an operation. In addition, since the endoscope is disposed outside the barrel, it is possible to reduce the outer diameter of the barrel and uniformly maintain a visual direction of the endoscope even when the barrel is rotated. Further, since the rotation function is added to both the barrel and the surgical instrument insertion hole, more convenient operation is possible.