Abstract: The invention is related to an instrument for endoscopic surgery. The instrument comprises a casing 10, further comprises a sliding tube 16 which extends into the casing with its proximal end 20 and which is disposed longitudinally slidable with respect to the casing by means of an actuating mechanism 38, further comprises an electrode tube 18 which extends through the sliding tube 16, which extends into the casing with its proximal end and is axially lockable therein, and further comprises two isolated wire pieces 32 which extend through the inside of the electrode tube 18.