PURPOSE: To develop a duct in the lump of powdery matter by introducing a duct, while keeping its compact shape, to a specific location in the lump of powdery matter holding one end of the duct in a fixed state and moving the other end toward the outside the lump of the powdery matter.

CONSTITUTION: A ring shape duct 1 is compressed in its axis direction so as to shorten the length and reinforced with spiral wires to be contained in a container 2. The container 2 is driven by a wire rope 11 connected to an opening 9 and can proceed or retire in the powder matter. A cap 6 for the container 2 to proceed blocks the open end 5 with the pressure of the powder matter and facilitates the proceeding of the container 2. For retreating the container 2, the cap 6 is held in the powder matter with a flange 7, removed from the container 2 and fix the bottom end of the duct 1 so that the duct 1 can be developed at a specific position in the powder matter.