To enable distinct confirmation of a lifting-lowering tool by a lifting- lowering person, and to carry out safe lifting and lowering by fixing the original tip of an optical fiber near an inlet in a manhole and installing a tip section to the lifting-lowering tool.

Optical fibers 2 are housed in a housing case 4 fixed onto the internal surface of the manhole 1 by fixing bands 6. Footstep fittings made of a metal are used as the lifting-lowering tools 3, and the tools 3 are mounted by burying anchor sections in the wall of the manhole 1. Original tips 2a as light-collecting sections are set up near the inlet of the manhole 1 and tips 2b as light-emitting sections to each lifting-lowering tool 3 in the optical fibers 2, the optical fibers are branched two by two from branch ports in the vicinity of each lifting-lowering tool 3, and each lifting-lowering tool 3 is supplied with light. Since light fed from the original tips 2a of the optical fibers 2 is emitted from the tip sections 2b fitted to the lifting-lowering tools 3 through the insides of the optical fibers 2, a lifting-lowering person can confirm the lifting-lowering tools 3 surely, and lifting and lowering can be conducted safely.