An insertion assisting tool (60) is provided and includes a multi-lumen tube (64) which has a tip end surface, a base end surface and an outer peripheral surface and in which each of an insertion path (70) for inserting the insertion portion of an endoscope therein and a fluid tube (72,74) formed separately from the insertion path is formed so as to penetrate from the tip end surface to the base end surface. An opening (80,90) is formed at the outer peripheral surface so as to communicate with the tube. The tube is closed at a position closer to the tip end surface side than the opening.
