To be able to collect a sample at the targeted depth position easily and securely by eliminating the possibility that a pile hole infill on the way to the targeted depth could be attached around the undersurface of a upper external cylinder and the top face of a lower external cylinder, and enabling operation only by the lifting performance of an operation bar.
When the undersurface 22 of a upper external cylinder 20 is nearly stuck to the top face 31 of a lower external cylinder 30 with a sampling port 10 of an internal cylinder 1 closed by the upper external cylinder 20, a sampling device 40 is lowered (a). Holding the internal cylinder 1 at the sampling position, an operation bar 15 is lifted from a ground to pull up only the upper external cylinder 20, and causes the sampling port 10 to open. Then a pile hole infill is taken in the internal cylinder 1. Next, the operation bar 15 is lifted to pull up the lower external cylinder 30, causing the sampling port 10 to close, and the sampling device 40 is lifted on the ground.
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