Embodiments of the invention provide a surgical instrument having an end-effector located on the end of a rotatable shaft, the shaft projecting from a handle. In order to provide for easy control of the shaft rotation a thumbwheel is provided at the proximal end of the handle, which controls the rotation of the shaft, and hence the rotational orientation of the end-effector. The end-effector is capable of several different operations, including grasping, cutting, and sealing and/or coagulating tissue, and one of the operations is controlled by a switch located on the upper surface of the proximal end of the handle. Specifically, the switch is oriented on the handle so as to be generally above the thumbwheel, in a relative position to the thumbwheel so that both the thumbwheel and the switch may be activated by the user's thumb, without the user having to alter his grip on the handle with his other fingers. In one embodiment of the invention the switch is therefore vertically oriented above the thumbwheel. Such a configuration provides for an ergonomic arrangement that increases the ease of use of the instrument by the user. <；Figure 34>；
