To make a caster easily attachable to and detachable from any moving object by interposing a detachable joining body between moving object and the caster, and attaching the caster.

This caster 1 is composed of a rolling body 2 and a rolling body holding part 3. The rolling body 2 is spherically formed of a raw material such as metal or plastic, and is held by the rolling body holding part 3 freely to roll, and thereby, the slipping-off of the rolling body 2 is prevented by a slipping-off preventing part 33. The caster 1 is attached by interposing a detachable joining body 4 between a moving object 6 and the caster 1. The joining body 4 is composed of a pair of joining tapes 4a, 4b, one joining tape 4 is stuck on a lower surface of the moving object 6, and the other joining tape 4b is stuck on an upper surface of a base part 31 of the rolling body holding part 3, and both tapes 4a, 4b are stuck with each other. It is thus possible to attach the caster 1 to every moving object 6, and it is also possible to easily attach or detach the caster 1.