A treatment instrument for joining treating living tissue (L1, L2) each other (12), holding member and a pair (52, 54), the holding member of said at least one pair to hold the living tissue to be treated forming joint (C) is by joining the living tissues together by supplying energy to living tissue are connected energy source (14) of with is provided in at least one, and held by the holding member of the pair To assist energy output section (92, 94), in maintaining the joined state of the junction, the junction maintains auxiliary portion for covering with a material that prevents the penetration of moisture to the surface of the joint of the living tissue (92a , 94a I and a 396,398) 162a, 164a 192a, 194a 202,204,206 180,212a, 214a 224,234 262 372a, 386a.生体組織(L1,L2)同士を接合処置するための治療用処置具(12)は、処置対象の生体組織を保持する少なくとも1対の保持部材(52,54)と、前記1対の保持部材の少なくとも一方に設けられているとともにエネルギ源(14)に接続され、前記1対の保持部材で保持した生体組織にエネルギを供給して生体組織同士を接合して接合部(C)を形成するエネルギ出力部(92,94)と、前記接合部の接合状態を維持するのを補助するため、生体組織の接合部の表層を水分の浸透を防止する物質で覆うための接合維持補助部(92a,94a;162a,164a;192a,194a;202,204,206;180,212a,214a;224,234;262;372a,386a;396,398)とを備えている。
