Provided is a guide sheath that is maintained in a desired shape and at a desired position even after a dilator has been pulled out therefrom so that the guide sheath can guide an insertion section to an appropriate position. A cylindrical guide sheath that guides an insertion section of a medical device to be inserted into a body cavity includes a base-end opening that is provided at a base end of a guide sheath body and into which the insertion section is inserted a distal-end opening that is provided at a distal end of the guide sheath body and from which the insertion section extends out and a shape maintainer that extends in an axial direction at an inner surface of the guide sheath body and has photo-curable resin that is cured by light.
