PURPOSE: To prevent the destruction of a side wall and greatly reduce the labor time by forming a sampler and a core taking-out tube in an integral form and carrying out the standard penetration test and the core sampling only through the rising and lowering of the equipment in one time.

CONSTITUTION: A boring rod 1 is pulled up for an outer pipe 2, and a male screw 6b is tightened with a female screw 6a by turning the boring rod 1, and at the same time, a boring rod side clutch 7b is joined with an outer pipe side clutch 7a. When the top end of the bit 4 of the outer pipe 2 reaches the hole bottom, the boring rod 1 is turned leftward, and the screwing of the screws 6a and 6b of a sampler 5 is released, and a free state is produced, and the sampler 5 is lowered to the hole bottom, and the specific penetration test is carried out. After the completion of the test, the sampler 5 is pulled up to the upper rnd part 3 of the outer pipe, and the boring rod 1 is turned rightward, and the screws 6a and 6b are screwed. Since the clutches 7a and 7b are fitted, the outer pipe 2 and the bit 4 are revolved each time when the boring rod 1 is turned rightward, and the excavation and the sampling of the geological feature core are carried out.