An insertion assist system includes a guide member and a shift member. The guide member brings an outside bend of a peripheral surface of an insertion body into contact with a guide surface of the guide member. The shift member shifts a direction of the distal end of the insertion body. The shift member comes into contact with an inside bend of the peripheral surface of the insertion body when the insertion body is bent. The shift member bends the insertion body toward the guide surface about the guide surface as a fulcrum when the shift member comes into contact with the inside bend and bends the insertion body.
