Provided is a grasper including an introduction tube that is capable of being inserted into a body cavity an operational elongate body that is inserted into the introduction tube so as to advance and retract and a clip that is attached to a distal end portion of the introduction tube and is operated by the relative movement between the operational elongate body and the introduction tube so as to grasp a body tissue, then is indwelled in a body. The clip has a plurality of grasping arms which are operated to be moved by the operational elongate body or the introduction tube, at least in a direction where the grasping arms are closed, so as to grasp the body tissue and a retracting portion which retracts a portion of the body tissue between the plurality of grasping arms.
