In the method suitable for tissue fusion or coagulation after the commencement of treatment of the tissue, i.e., after completion of a first phase, a second phase is commenced, during which the biological tissue is treated with moderate energy for a certain specified process time. The specification of a functional relationship between the tissue resistance and the output voltage of a supplying source enables the process in phase II to not fall below a minimum treatment time, avoiding premature drying-out of the tissue. A sufficient and reliable bonding of the participating proteins in a moist milieu is reached.
