the invention relates to a bipolar coagulation instrument having a hollow shaft configured as a suction and / or flushing tube and having two electrodes that are electrically insulated with respect to one another and extend beyond the distal end of the shaft . to provide a bipolar coagulation instrument that is both of simple structure and ensures an effective suction / flushing capacity , it is proposed with the invention that the hollow shaft should consist of two electrically conductive tubes coaxially mounted on one another that are electrically insulated with respect to one another and from the outside , so that the tubes constitute the electrodes .