Surgical instrument: with a first branch which has two first sealing jaws (19, 20) arranged at a distance from each other and delimiting between them a first groove, with an electrically insulating cutting electrode carrier which has a foot arranged in the groove and having a foot surface (23 a), which is set back relative to the sealing electrodes (25, 26) arranged on the first sealing jaws (19, 20) and from which a wall-like extension extends away at a distance from the first sealing jaws (19, 20) of the first branch, with a cutting electrode which is embedded in the cutting electrode carrier with an exposed end face, with a second branch which has two second sealing jaws (36, 37) arranged at a distance from each other and delimiting between them a second groove, wherein the branches (15, 16) are movable towards each other and away from each other in a movement direction, in order to be closed and opened, with a counter-bearing for the cutting electrode arranged in the second groove, wherein the counter-bearing has a tissue-support surface which, in the closed state of the branches (15, 16), is set back relative to the sealing electrodes (39, 40) of the second sealing jaws (36, 37) and forms a contact surface for the biological tissue, wherein when the branches (15, 16) are closed, in the movement direction between the tissue-support surface of the counter-bearing and the foot surface of the foot, and transversely to the movement direction between the extension and the first sealing jaws (19, 36), and between the extension and the second sealing jaws (20, 37), tissue-receiving spaces (53, 54) are formed which are delimited vertically between the foot and the tissue-support surface of the counter-bearing, and the horizontal extension of which is determined by the distance between the wall-like extension and the sealing jaws (19, 36; 20, 37), wherein the sealing jaws (19, 36; 20, 37) in pairs establish a respective sealing gap (45, 46), and wherein the first and the second sealing jaws (19, 26; 20, 37) are rounded towards the tissue-receiving spaces (53, 54). with a first branch which has two first sealing jaws (19, 20) arranged at a distance from each other and delimiting between them a first groove, with an electrically insulating cutting electrode carrier which has a foot arranged in the groove and having a foot surface (23 a), which is set back relative to the sealing electrodes (25, 26) arranged on the first sealing jaws (19, 20) and from which a wall-like extension extends away at a distance from the first sealing jaws (19, 20) of the first branch, with a cutting electrode which is embedded in the cutting electrode carrier with an exposed end face, with a second branch which has two second sealing jaws (36, 37) arranged at a distance from each other and delimiting between them a second groove, wherein the branches (15, 16) are movable towards each other and away from each other in a movement direction, in order to be closed and opened, with a counter-bearing for the cutting electrode arranged in the second groove, wherein the counter-bearing has a tissue-support surface which, in the closed state of the branches (15, 16), is set back relative to the sealing electrodes (39, 40) of the second sealing jaws (36, 37) and forms a contact surface for the biological tissue, wherein when the branches (15, 16) are closed, in the movement direction between the tissue-support surface of the counter-bearing and the foot surface of the foot, and transversely to the movement direction between the extension and the first sealing jaws (19, 36), and between the extension and the second sealing jaws (20, 37), tissue-receiving spaces (53, 54) are formed which are delimited vertically between the foot and the tissue-support surface of the counter-bearing, and the horizontal extension of which is determined by the distance between the wall-like extension and the sealing jaws (19, 36; 20, 37), wherein the sealing jaws (19, 36; 20, 37) in pairs establish a respective sealing gap (45, 46), and wherein the first and the second sealing jaws (19, 26; 20, 37) are rounded towards the tissue-receiving spaces (53, 54).