To make a device applicable to various kinds of tool, which is connected to the tool without generating looseness, which can be wound around a wrist of user upon non-use, and which can be used at work surely for assuring safety.

A hook 3 releasably connected to a tool is arranged at one end of a belt-like body 1 while an annular part 4 is formed at the other end, and a ring-like member 5 releasably connecting the hook 3 is arranged at the annular part 4. The belt-like body 1 is formed of woven material, whose whole outer surface is roughly formed and whose length is about two times (about 40cm) as large as the circumferential length of a user's wrist. Upon use, a tool is connected to the body 1 through the hook 3 to prevent accidental drop of the tool so as to assure the safety. Upon non-use, e.g. at a lunch time, the body 1 is wound around the wrist while the hook 3 is connected to the annular member 5 to preventing it from being forgotten or lost before the re-start of work.