Abstract: A driving device of a jaw crusher of attachment type comprising a hydraulic cylinder having a rod connected with a movable member; a hydraulic source provided on a body of a hydraulic excavator having a mobile travel device; and a control mechanism for supplying a hydraulic pressure to the hydraulic cylinder so that the rod is extended and retracted reciprocatively and detecting a hydraulic pressure at an extension side of the hydraulic cylinder and a retraction side thereof, thus switching extension and retraction operations of the rod to each other when the hydraulic pressure at the extension side of the hydraulic cylinder or the retraction side thereof exceeds a predetermined value.