An energy treatment device 10 includes a probe 3, a sheath unit 4, a movable handle unit 5 and an acceleration portion 100. The acceleration portion 100 is provided in the movable handle unit 5, and accelerates the elastic deformation of the movable handle unit 5 in a direction in which the movable handle unit 5 has received the reaction force when the movable handle unit 5 opens and closes to a fixed side for the treatment operation and the movable handle unit 5 receives a reaction force from a treatment target due to an open-close operations.
