PURPOSE: To provide a caster section height adjusting system capable of resolving the nonuniformity of the lock state and having excellent workability by vertically moving a caster supported with a wheel on a caster shaft screwed to a frame for height adjustment.

CONSTITUTION: A height adjusting nut 3 is integrally provided on the caster shaft 4 of a caster 1, and a nut rotation stop plate 11 with a coupling piece 13 coupled with the outer shape of the nut 3 and a spring 12 exciting the plate 11 in the direction apart from a frame 5 are inserted between the frame 5 of a device and the nut 3 to constitute a caster height adjusting system. End sections of the spring 12 are hooked on the frame 5 and the plate 11 respectively. The caster shaft 4 supports a wheel and is screwed to the frame 5.