An energy treatment device includes a probe, a sheath unit, a fixed handle, a movable handle unit, a rotation axis, a jaw and a thickness-reduced portion. The thickness-reduced portion is one part of the jaw and is provided between the rotation axis and a distal end of the jaw. The thickness-reduced portion flexes in response to a reaction force when one part of the jaw receives the reaction force from a treatment target due to the opening and closing of the movable handle unit to the treatment target. The thickness-reduced portion prevents the deformation of the other parts of the jaw by flexing.
