Patent ID: 7150752

Claim:
An endoscopic instrument, an operation portion of an endoscope having a mouth ring of a channel which is inserted through a main body of said endoscopic instrument used in combination with said endoscope, said mouth ring portion having a protrusion portion which protrudes from said operation portion toward the outer side and a flange portion arranged at an edge portion of said protrusion portion, said endoscopic instrument main body having an attachment portion attached to said mouth ring, wherein said attachment portion has a mouth ring fitting portion fitted to said mouth ring portion, said mouth ring fitting portion having: a cylindrical shaft portion including at a shaft center portion a fitting hole portion fitted to said mouth ring portion; and an engagement operation portion which is supported on said shaft portion and operates to switch between a flange portion insertion position at which said flange portion of said mouth ring portion can be inserted and an engagement position at which it can be engaged with said protrusion portion of said mouth ring.