ENDOSCOPIC SURGICAL INSTRUMENT

PROBLEM TO BE SOLVED: To provide an endoscopic surgical instrument improving the cleaning characteristics of the endoscopic surgical instrument in the case of a TFT configuration design.SOLUTION: An endoscopic surgical instrument 1 including an outside jacket 2 of hose shape includes an inside jacket 4 of the same hose shape supported in a relatively displaceable manner in the outside jacket 2, and an instrument head 6 of sleeve or shaft shape formed at or mounted to an end section of the inside jacket 4. An RF electrode 8 of needle shape which is electrically insulated and freely projected in an axial direction over the end part of the instrument head 6 and to which the electric supply line is transmitted through the inside jacket 4, is fixed to the instrument head 6. The instrument head 6 is formed with a cleaning passage extended at least in the axial direction and opened at the end of the instrument head 6 on both sides.