An energy treatment device includes, a first power accumulator which accumulates electric power; a clock generation portion which generates a clock signal based on the electric power; a controller which uses the clock signal to control supply of an energy to be used for treatment at a treatment portion; a trigger portion which generates a trigger signal that permits the clock generation portion and the first power accumulator to be electrically connected so that the controller receives the clock signal; and a switching portion which, in accordance with a presence/absence of the trigger signal at the trigger portion, switches between a connected state, where the clock generation portion and the first power accumulator are electrically connected, and a disconnected state, where the clock generation portion and the first power accumulator are electrically separated.