Hydrogen is an excellent antioxidant molecule that exists in nature in a vapor state. There are many challenges involved in handling and stabilizing it. We have to control the amount of hydrogen as much as possible. We also estimate whether the hydrogen will be taken in a human body. Thereby we produce the products, and we have received many voices of a bodily sensation. We are measuring only hydrogen directly by gas-chromatography method. We propose a criterion that is an indicator of hydrogen. We will introduce “Hydro-calcium powder (HCP)” that is a hydrogen material. Of course, based on evidence.