PROBLEM TO BE SOLVED: To provide a base capable of sucking water to an upper part by an amount equal to a sphagnum material by the base itself and continuously and constantly supplying water to a surface region for environmental control and biological cultivation by only reserving the water at a bottom part without pumping up the water and without being limited by material.SOLUTION: There is provided a wet base having a structure to reserve a liquid in a region and to make reserved solution flow out when a liquid level exceeds a definite limit. A greening material or a material capable of reserving the liquid is fixed to suck up the solution from the water reserving region, and the lowest position to supply the solution downward from an upper part of the fixed material is set to be higher than the highest water level of a water reserving part 5' or a water-shielding member 6 which shields the solution is arranged at the lowest position.【課題】水をポンプアップをすることなく、また素材に限定されることなく底部に水を溜めておくだけで、基盤自身がミズゴケ素材と同等に水を上部に吸い上げ、環境を調整や生物養成をする表面領域に水を持続的かつ一定に供給できる基盤について提供する。【解決手段】液体を溜める領域に一定以上の水位を超えると溜められた溶液が流れ出る構造を設け、この水溜め領域から溶液を引き上げるように緑化資材あるいは液体を保持することのできる資材を固定し、かつ固定された資材の上方から下方に向かって溶液を供給させる最下位置を、水溜め部５’に設けた最高水位よりも高い位置に設定するか、この最下位置に溶液を遮断する水遮断体６を設ける。【選択図】図１
