Abstract: An arrangement (1) for electrothermally treating the human body or an animal body, in particular for tissue coagulation or electrotomy, includes two electrodes (3, 4) for insertion into the body to be treated. The two electrodes (3, 4) are electrically insulated from each other and are disposed at a distance from each other to produce an electric or electromagnetic field heating the body tissue in the treatment area, and each electrode is connected by a feed line with a power source arranged outside the body. An elongate catheter (2) is provided for joint insertion of the two electrodes (3, 4) into the body, which are staggered in relation to each other in the axial direction of the catheter (2) and connected to the catheter (2) or a component thereof.