A robot arm with a robot-hand drive device, which has at least three electric motors arranged in an arm boom of the robot arm for driving a multi-axis robot hand of the arm boom, each electric motor having an electric rotor, each of which has a motor shaft. The at least three electric motors are arranged in the interior of a common housing cylinder block, in such a way that each rotor lies in a separate cylinder sector of the housing cylinder block, more specifically with its respective motor shaft running parallel to the center axis of the housing cylinder block, said axis running longitudinally along the arm boom.