To provide a work machine which, in a configuration provided with a closed-circuit pump and an open-circuit pump, is capable of stabilizing respective pump operations of the closed-circuit pump and the open-circuit pump and of improving the mountability of the closed-circuit pump and the open-circuit pump. The present invention is provided with a closed circuit in which a closed-circuit pump and a boom cylinder are connected annularly, and an open circuit which has an open-circuit pump for making hydraulic fluid flow in from a reservoir and flow out and a connection passage capable of introducing hydraulic fluid into the closed circuit, wherein the closed-circuit pump is installed above the open-circuit pump.