PROBLEM TO BE SOLVED: To securely coagulate a dissected surface by sticking or inserting a tissue coagulator into a portion of a dissection line, and to miniaturize the tissue coagulator to such a size as can be used in an endoscopic surgery.SOLUTION: A tissue coagulator has needles 11 with heaters 13 disposed on the whole or in a part within. The needles 11 are stuck or inserted into the periphery of a tumor or along a dissection line, and heated to coagulate the tissue. A plurality of needles 11 are erected at regular intervals on one surface of a base part 15, and the intervals of the needles 11 are retained uniform. The tissue coagulator is stuck or inserted into the periphery of the tumor or an area along the dissection line, so that a dissected surface can be securely coagulated, and bleeding when the tumor is dissected can be controlled.
