Pushing or pulling operation arranged on the side where the gripping part 7 extends on the outer peripheral side surface 6g provided in the insertion part 5, the endoscope operating part 6, the gripping part 7 and the endoscope operating part 6 A treatment instrument mounting portion A having a detachable finger grip 52 and a treatment instrument mounting portion A which is detachable, and a treatment instrument provided on the side where the gripping portion 7 extends on the outer peripheral side surface 6g of the endoscope operation portion 6. When the treatment instrument operation section 51 is mounted on the mounting section A, the finger placement section B is located on the proximal end side of the finger hook section 52 and on the distal end side of the grip section 7.挿入部５と、内視鏡操作部６と、把持部７と、内視鏡操作部６に設けられた、外周側面６ｇにおける把持部７が延出する側に配置される押し操作または引き操作が可能な指掛け部５２を有する処置具操作部５１が着脱自在な処置具装着部Ａと、内視鏡操作部６の外周側面６ｇにおける把持部７が延出する側に設けられた、処置具装着部Ａに処置具操作部５１が装着されたときに、指掛け部５２の基端側であって把持部７よりも先端側に位置する指配置部Ｂと、を具備する。
