To provide a treatment instrument that combines a capability to grip a target tissue and a capability to resect and ablate the target tissue without the need to interchange left and right devices or adjust a field of view of an endoscope, which can reduce burden on a surgeon. A high frequency forceps includes a pair of forceps pieces configured to open and close on a pivot and equipped with incision blades adapted to pass a high-frequency current to a living tissue, in which the incision blades are formed, respectively, on opposite faces of the pair of forceps pieces, extending from a side of the pivot to a distal side； and the incision blades are spaced away from each other when the pair of forceps pieces is closed.
