Electrosurgical instrument and electrosurgical apparatus

An electrosurgical instrument for sealing or cutting tissue, comprising

• an instrument shaft comprising a transmission line for conveying microwave or [and/or] radiofrequency electromagnetic energy;
• a first jaw attached to the instrument shaft and including a first surface,
• a second jaw attached to the instrument shaft and including a second surface,
• a first electrode for emitting microwave or radiofrequency energy,
• a second electrode for emitting microwave or radiofrequency energy,
• a third electrode for emitting microwave or radiofrequency energy, and
• a first isolating portion electrically isolating the first electrode from the second electrode,
• wherein the first jaw and the second jaw can be moved between an open position, in which the tissue can be inserted between the first surface and the second surface, and a closed position, in which the first and second surfaces are brought together to clamp the tissue therebetween,
• wherein the first electrode and the second electrode are arranged on the first jaw,
• wherein the third electrode is arranged on the second jaw,
• wherein the first isolating portion is made from an elastically deformable material,
• wherein the first electrode is attached to and supported by the first isolating portion so that the first electrode is movable relative to the second electrode upon application of pressure on the first electrode, and
• wherein the first electrode is made from an electrically conductive material and interlocks with the first isolating portion.