Patent ID: 7935114

Claim:
A treatment device which applies energy to a living tissue, comprising: first and second holding portions which are configured to relatively move with respect to each other and which include a holding surface to hold the living tissue, respectively; an output portion disposed on the holding surface of at least one of the first holding portion and the second holding portion, configured to come into contact with the living tissue when the living tissue is held by the first and second holding portions, and to apply the energy from an energy source to the living tissue as an object to be treated, the output portion configured to generate a fluid including a gas and a body liquid having a temperature higher than a normal temperature and a pressure higher than a normal pressure, from the living tissue, by the energy supplied from the energy source; an edge portion configured and disposed to arrange the output portion, disposed on the holding surface on an inner side of the edge portion, to come into contact with the living tissue when the living tissue is held by the first and second holding portions; a gutter having a surface which is lower than a surface on which the output portion is configured to come into contact with the living tissue and which gutter surface does not directly come into contact with the living tissue, with a closed space being formed between the surface of the gutter and the living tissue when the living tissue is held by the first and second holding portions, the gutter being filled with the fluid including the gas and the body liquid having the high pressure from the living tissue; and an opening disposed on the holding portion on which the output portion is disposed, of the first and second holding portions, the opening communicating with the gutter, and configured to urge the fluid including the gas and the body liquid having the high pressure in the gutter to be discharged to a position remote from a welding surface of the living tissue, while the living tissue is in contact with the edge portion, wherein the gutter is formed on the output portion.