A hydraulic shovel including a selection means for an engine which is capable of arbitrarily selecting either of an isochronous control and a droop control, and a traveling detection means for detecting the traveling state of a traveling device. The hydraulic shovel further includes a control means for the engine which selects the isochronous control when the traveling detection means detects the traveling state to maintain the rotational speed of the engine during rated operation while an output is increased, and selects the droop control when the traveling detection means does not detect the traveling state to set the rotational speed of the engine lower than that during the rated operation while the output is increased.