Regarding the calcining and extraction of silica (SiO2) contained in rice husks at about 20%, this report refers to the pickling firing method 1) by Dr. Umeda et al. This is a report of high-purity production. The research results show that high-purity amorphous silica (purity 99.2% white silica) can be produced by production under optimum pickling and firing conditions, and the crushed product has excellent water-soluble performance (85 mg / L). We confirmed and succeeded in product production.