To provide an internal indwelling appliance facilitating an insertion and extraction relative to a fistula of a patient and capable of preventing development of the ulcer or the buried bumper syndrome.

This internal indwelling appliance A comprises a cylindrical member 11 to be installed in the fistula, and an internal retaining member 20 to be installed in the stomach. The internal retaining member 20 comprises belt-shaped members 22a and 22b curvedly extending from distal end opening edge parts of a tubular member 11 toward the outside tip and connecting their distal parts to each other and having flexibility, and film members 23a and 23b provided in a part in the side of a tubular member 11 such as the belt-shaped member 22a and the like, forming a dome-shaped part with the belt-shaped member 22a and the like and having flexibility. This appliance is provided with notches 26a and 26b at the center of the outer circumferential edge part 25a of the film member 23a and the like, folding groove part 27a and the like extending from the notch part 26a and the like to the side of the tubular member 11, and a folding groove part 28a and the like extending from the outer circumferential edge part 25a of the film member 23a and the like toward the side of the tubular member 11.