An endoscope insertion aid includes: a tubular member which allows an insertion portion of an endoscope to be passed through in a manner being capable of moving forward and backward. A holding unit, which is provided on an outer peripheral side of the tubular member, can be inflated and deflated. A thread-like member, which is connected at one end to the tubular member and passed at the other end into a channel, extends from an opening of the channel. A thread-like member fixing unit which restrains the thread-like member and thereby restricts movement of the tubular member. A restraining member which supplies and discharges the fluid into/from the holding unit, being disposed to the insertion portion, being connected at one end to the tubular member, extends at the other end to the proximal end side of the insertion portion. A restraining member fixing unit which holds the tubular member.
