PURPOSE: To enable the extraction of soil different in the texture within a fixed time, by moving a column set comprising a trap cylinder, a column, a suction cylinder and the like upward in a fixed time to suck an extraction liquid into a suction cylinder with a suction piston.

CONSTITUTION: Scores of column sets 13 which comprise a trap cylinder 10A, an adaptor 11, a column 12, an adaptor 13 with a stop cock, a suction cylinder 10B and a suction piston 14 are mounted at an operating section A in which upper and lower cylinder mounting plates 5A and 5B are integrated with a guide struts 4A and 4B and a strut 5B. After the operating section A is lowered to the position of a stationary plate 6 with a manual handle 1, the extraction time is set with a dial of a transmission gear 8, the operating section A is forced up with a motor 7 until reaching a limit switch 2A while an extraction liquid of the cylinder 10A is sucked into the cylinder 10B via soil in the column 12. In addition, the cylinder 10B and the piston 14 are removed to recover the extraction liquid.