PURPOSE: To quickly execute an efficient continuous work, reduce an extent of occupying road breadth, improve safety, save labor and shorten a construction period respectively at the time of excavating a channel for piping.

CONSTITUTION: A casing 11 housing a screw auger is held in such state as freely liftable with a lift device 9 laid on a vehicle 10. This casing 11 is provided with a lengthwise slit type opening on the side thereof along the travel direction of the vehicle 10. Also, a reciprocating cutting machine 18 with a vertically oscillating ladder type cutter is laid in the slit type opening.