PURPOSE: To raise the sampling rate of soil to be treated by a method in which soil taken from the shoe on the tip end is wrapped by a lubricated flexible tube sent out from between the tip end of a sampling tube and the shoe.

CONSTITUTION: A piston rod 1 is fixed to a frame, and a boring rod 7 is pushed down to a given penetration length. In this case, an outer tube 4 and a sampling tube 3 are also penetrated into soil to be treated concurrently, and soil taken from the shoe 5 on the tip end is wrapped by a rublicated flexible tube 13 sent out of a tube sending port 23 between the tip end 3A of the sampling tube 3 and the shoe 5. The soil enters the sampling tube 3 with lessened friction with the inner surface of the sampling tube 3. The rod 7 and the coupling 6 are removed, the sampling tube 3 and the outer tube 4 are allowed to stand until the soil is hardened, and the soil is pulled up along with the tubes 3 and 4.