To enable a person to ascend/descend safely while perceiving elevating means clearly by arranging optical fibers inside, and disposing a base end converging part near an entrance while disposing tip light emitting parts in appropriate places inside.

A storage case 4 is a cylindrical pipe having ten branch ports corresponding to elevating means 3, and the upper part of the case 4 is covered with a cap 5 with a chain. In this case, twenty optical fibers in total are disposed inside the case 4, two to each elevating means 3. The base ends of all the optical fibers 2 are provided at the upper end of the storage case 4 and exposed near the entrance of a manhole 1 by opening the cap 5. The tips of the optical fibers 2 are respectively exposed from the respective branch ports in order to distribute two to each elevating means 3. At the time of elevating the manhole 1, the cap 5 is detached, and an adaptor is installed at the upper end of the case 4. A person can thereby ascend/descend safely.