The surgical instrument has longitudinal shaft (11) having a proximal end and a distal end (12). A tool (13) is arranged on the distal end. A handle (18) is arranged on the proximal end. An actuating device (24) is arranged on the handle. A transmission unit (29,29a,29b) is extended through the shaft and is movable in shaft to transmit a movement of the actuating device to the tool. A sealing element (34) made of hydrophobic material is arranged in the shaft.
