To provide reducing water having a strong redox power and lasting in its effect, and its bulk production method.

The utilization of a synergic effect of low radioactivity and high-rate growing light has enabled the reducing water, strong/weak alkali reducing water and strong/weak acid functional water to be simply prepared, and by applying the nature of the reducing water, various kind of ion ball and ion-reducing ball can be prepared. Further, by applying the reducing water to a general rock, the preparation of a functional rock having both of the low radioactivity and high-rate growing light (far infrared rays 4-14μ) radiation rate has become possible, and by the method of firing pottery and porcelain, the preparation of a similar functional artificial ore has also become possible.