A first step of guiding the opening of the lumen tissue endoscope having a channel, selective cannulation method to the lumen tissue with a bifurcation, the endoscope through the opening through the channel two locations and a second step of inserting the tip of iodine treatment instrument, the opposite tube wall up to the bifurcation from the opening of the lumen tissue by deforming the distal end side of the endoscope treatment tool a fourth step of slidably moving to the branch portion while in contact with the tube wall and the third step of contacting the distal end side of the endoscopic treatment tool in the tip of the endoscopic treatment tool, the and a, and a fifth step of inserting into the branch lumen predetermined branched from the branch portion to the tip of the endoscopic treatment tool.分岐部を有する管腔組織への選択的カニュレーション方法は、チャンネルを有する内視鏡を前記管腔組織の開口部に案内する第1ステップと、前記チャンネルを介して前記開口部から内視鏡用処置具の先端を挿入する第2ステップと、前記内視鏡用処置具の先端側を変形させて前記管腔組織の前記開口部から前記分岐部に至るまでの管壁の対向する二箇所に前記内視鏡用処置具の先端側を接触させる第3ステップと、前記内視鏡用処置具の先端を前記管壁に接触させつつ前記分岐部まで摺動移動させる第4ステップと、前記内視鏡用処置具の先端を前記分岐部から分岐された所定の分岐管腔へ挿入する第5ステップと、を備える。
