A robot arm capable of being driven with a small force while having an enhanced rigidity includes a joint unit formed by stacking a plurality of link modules up against each other, and at least one driving device allowing the joint unit to pivot along at least one axis, wherein the driving device includes a cable disposed to pass through the plurality of link modules a plurality of times, a plurality of multi-turn pulleys configured to change a path of the cable when the cable passes therethrough, such that the cable passes through the plurality of link modules, and a driving unit configured to pull or push the cable such that the joint unit pivots.
