The energy treatment instrument includes a first gripping piece and a second gripping piece which is opened and closed between the first gripping piece and grips a blood vessel between the first gripping piece and the first gripping piece. A first mode in which the blood vessel is coagulated when there is no branch of the blood within a predetermined range from a position at which the blood vessel is gripped, and a second mode in which the branch of the blood vessel exists within the predetermined range And a second mode in which the blood vessel is coagulated when performing the operation.エネルギー処置具は、第1の把持片と、前記第1の把持片との間が開閉し、前記第1の把持片との間で血管を把持する第2の把持片と、を備える。前記エネルギー処置具は、前記血管が把持される位置から所定の範囲内に血管の分岐が存在しない際に前記血管を凝固させる第1のモードと、前記血管の分岐が前記所定の範囲内に存在する際に前記血管を凝固させる第2のモードと、の間で作動状態が切り替えられる。
