Abstract: An optical fiber bundle that has better ultraviolet resistance characteristics at a wavelength range of 150 to 250 nm and that can be readily and cheaply manufactured with no risk of, for example, explosion during manufacturing and its manufacturing method are provided. In the optical fiber bundle, optical fibers including a core mainly containing silica glass and a cladding containing silica glass and fluorine are bundled and accommodated in a container. This container has optically transparent ends, accommodates hydrogen or deuterium as well as the optical fibers, and is sealed. The capacity of the container is 10 times or less as large as the volume of glass of the optical fibers.