To provide a control method of a working module such as a hydraulic grab and a device which excavates a hole and removes obstacles from the hole extremely effectively (effective as hardware, time, and cost) and carry out a plurality of works through the working module.

The rotation of a drill rod 2 is transmitted to a working module 5 through a rotary head housing 17 and a switch housing 15. And a work such as drilling is carried out thereby. The first directional rotation of the drill rod 2 is converted i-times faster or slower (i is the transmission ratio of the gear) than the rod by a gear 7 and transmitted to a hydraulic pump 9 through a trip-free structure 11. And a hydraulic cylinder 6 is driven by the hydraulic pump 9 to give the axial movement to the working module 5. A grab is closed by the axial movement for instance.