A caster device includes a support unit, two caster wheels, a resilient member, two friction wheels, and two protruding teeth units. Each of the caster wheels has an inner wheel surface and a plurality of meshing teeth that are angularly arranged and that are formed on the inner wheel surface. Each of the protruding teeth units includes a plurality of protruding teeth. The support unit is downwardly movable against a resilient force of the resilient member to a stop position, where each of the friction wheels is in frictional contact with the meshing teeth of a respective one of the caster wheels, and where the protruding teeth of each of the protruding teeth units are meshed with the meshing teeth of the respective one of the caster wheels.