To provide a revolving work unit which has a longitudinally compact arrangement space for a control valve, makes the arrangement space larger on a rear side, and can use a straight adapter for connecting a hydraulic hose to a control flap, to thereby facilitate attachment/detachment of the adapter, wherein the revolving work unit can lower the location of a step covering a front upper surface of a revolving stand.

The revolving work unit has the revolving stand 12 which is borne on a traveling device in a manner rotatable about a vertical revolving axis, and the control valve 31 having the control flaps connected thereto in one body in one direction, is arranged on a front side of the revolving stand at a location closer to a right or left end thereof. The control flaps control various hydraulic devices mounted in the revolving work unit. Then the control flaps of the control valve are arranged in a lateral direction such that a pressure oil feeding/returning port of each control flap faces rearward and that a spool S of each control flap is vertically extended. Further an upper side of the control valve is protruded from an upper surface of the revolving stand.