PURPOSE: To efficiently adsorption-recover rare substances such as U in sea water by setting wing-form bodies, in an ocean current, packed with an adsorbent for U, etc. and having many small openings at the upper and lower sides and by passing sea water through the bodies via the openings owing to the difference in water press. between the upper and lower sides due to the water current.

CONSTITUTION: Wing-form meshy bodies 1 are packed with adsorbent 3 for adsorbing rare substances such as U and Li contained in sea water, and bodies 1 are set in ocean current 4 at an attack angle of 0° or α°. Inverted wing-form bodies 1' are also set in current 4 similarly. When sea water flows along the upper and lower sides of bodies 1, 1', a water press. applied to the curved sides is lower than that applied to the flat sides, so that water penetrates into bodies 1, 1' from the flat sides through the small openings, and it is discharged from the curved sides through the small openings. During this time the water contacts to packed adsorbent 3 to allow U, Li, etc. to be adsorbed.