To provide a work machine that can suppress a steep fluctuation in engine power. The present invention includes an engine 11; a hydraulic pump 12 that is driven by the engine 11; a hydraulic actuator 17 that is driven by pressure oil discharged from the hydraulic pump 12; a motor generator 13 that drives the hydraulic pump 12; an electrical storage device 14 that transfers electric power with the motor generator 13; a load computing unit 21 that computes the load power of the engine 11; a vehicle body state management unit 22 that manages a vehicle body state including the state of the electrical storage device 14; an engine power fluctuation limitation unit 23 that computes second target power for limiting the increase rate and the decrease rate of the power of the engine 11 on the basis of the load power and the vehicle body state; a hydraulic power limitation unit 24 that limits the power of the hydraulic pump 12 on the basis of the second target power; and an assist power computation unit 25 that limits the power of the motor generator 13 on the basis of the second target power.