An endoscope plug body comprises a plug frame, a lid member and a plug member and shuts off an inside of a treatment instrument insertion channel from an outside. The plug frame is provided with annular projection portions, a plug body destruction portion and a plug-frame destruction operation portion. A flange portion is arranged between the annular plug portions and fitted to a base of the endoscope. The plug body destruction portion and the plug-frame destruction operation portion releases the lock state by destruction. The plug frame is cylindrical and communicates with a pipe line disposed inside the endoscope. The lid member is separate from the plug frame and has a lid portion disposed at an opening at the other end of the plug frame. The plug member is separate from the plug frame, formed of an elastic member and has a plug-member treatment instrument insertion portion.