To eliminate the risk in deformation of an outer circumferential face of a wheel, to reduce a whole size, and to switch over rotation of a wheel to a caster body and the locking/unlocking of rotation of the caster body to a rotation axis by only pushing-down operation of an operation pedal.

A double-wheel caster 100 includes: a rocking member 23 which rocks in order to switch over locking/unlocking of rotation of wheels 21R and 21L to the caster body 1; a hook 18 which is rocked by the rocking member 23 in order to switch over locking/unlocking of rotation of the caster body 1 to the rotation axis RS; and a knock mechanism for rocking the rocking member 23. The pushing-down amount of the knock member 7 and rotor 4 of the knock mechanism is switched over by pushing-down operation of the operation pedal PD, and the knock mechanism is arranged on a center axis of the rotation axis RS, and accommodated in the inside of the rotation axis RS and the caster body 1.