To make it possible to operate an excavator with one hand by constituting three-dimensionally an operating lever of a large number of joints.

When a bucket is rectilinearly moved to that side thereof, a driver grasps a grip section 23 of an operating lever and pushes it straight forward. Then, manipulated variable of a first link 21 is inputted in an electronic controller 12, operations of a moving direction and an angle of the front end of the an arm are carried out, operations of moving speeds and directions are performed on the basis of operational results, operating speeds of boom cylinder 8 and arm cylinder are carried out, and an electronic proportional valve 13 is driven to operate a directional control valve 14. As a result, the boom cylinder 8 and arm cylinder 9 and operated to operate the boom and arm. when the grip section 23 is rotated, an operation of an operating speed of a bucket cylinder 10 is performed with the electronic controller 12 to drive the electronic proportional valve 13, the direction control valve 14 is adjusted, and the bucket cylinder 10 is operated to operate the bucket.