A treatment system includes an energy source, a pair of holding portions, an output portion and a first channel. At least one of the holding portions is configured to relatively move with respect to the other holding portion. The output portion is disposed on at least one of the pair of holding portions and connected with the energy source. The output portion is configured to generate a fluid including a gas and/or a liquid from the living tissue by the energy supplied from the energy source. The first channel is disposed at a position close to the output portion. The first channel is configured to pass the fluid generated from the living tissue.
