Energy-using treatment tool

A treatment part of a treatment tool for treating target body tissue by applying energy thereto has the following: first and second jaws that can open and close relative to each other so as to be able to grasp and release body tissue including the target body tissue and surrounding tissue; a pair of first grasping parts that face each other, are provided inwards of the outer edges of the first and second jaws, respectively, and can grasp the target body tissue; an energy-release part, provided on at least one of the pair of first grasping parts, that can subject the target body tissue to energy for the purpose of treatment; and a pair of second grasping parts that are provided between the first grasping parts and the outer edges of the first and second jaws, respectively, and can grasp the tissue surrounding the target body tissue in a state in which said surrounding tissue is folded with respect to the target body tissue.