PURPOSE: To save energy by connecting a piston to one end of a pole swingably supported with a support member through a rod, providing a weight corresponding to a pump load and the like on the other end, and movably holding the rod with guide rollers.

CONSTITUTION: A motor 22 is driven to rotate a crank wheel, and a pole 9 fitted with a weight 10 on one end is put into a seesaw motion through a connecting rod 24 centering around a shaft 21. Next, a rod 13 is moved up and down between guide rollers 14 through universal joints 25, 27 and a connecting rod 26. Next, when a piston 3 is brought down, a ball check valve 16 is opened, and hot spring water and the like in a casing are entered into the piston 3. When the piston 3 is lifted, a ball check valve 15 is opened, and hot spring water and the like stored in an exploratory drilling hole A are entered to a suction pipe 5 through a suction port 5a, and let flow in the casing 2. Further, the hot spring water and the like in the piston 3 are pushed up with the piston 3 to flow in a discharge pipe 6, and discharged outward through a branch pipe 20.