A surgical instrument 10 suitable for sealing tissue includes a tool 15 with at least one branch 16 comprising an electrode unit 35, which consists of a sheet metal part 35. The part 35 is anchored in a positive manner in a plastic body 34. Strip sections 40, 41 of the metal part 35 extend into the plastic body 34, encompassing openings 42, 42 or slits 43, 43a, through which the plastic body 34 extends. A positive anchoring of the sheet metal part 35 in the plastic body 34 and minimizing of the heat introduction into the plastic body 34 is thus attained. The thermal capacity of the sheet metal part 35 and the thermal conductivity of the plastic body 34 are low, so that consistently positive coagulation results are reached even after repeated use in short succession, regardless of the initial temperature of the tissue contact surfaces 36.
