To provide a high-purity silica production method which can produce high-purity silica well suited for production of high-purity silicon for a solar cell with high efficiency and at low cost.SOLUTION: Extraction from diatomaceous earth with an acid is performed, in which impurities of an alkaline earth metal, an alkali metal, a transition metal and a post-transition metal are removed through a filter with washing with pure water, to thereby give silica with which sodium hydroxide is then reacted to give an aqueous alkali silicate solution (water glass). The water glass is passed through an ion exchange chelate resin and an anion exchange chelate resin to remove, as impurities, boron which is a metalloid and phosphorus which is a nonmetal. Once a desired purity of the silica is attained, an aqueous water glass solution is titrated with an acid to give a silica gel. The silica gel is dried at about 1,200°C or higher and the resultant is centrifugally separated and filtered to collect the silica in powder form and with high-purity. The silica is then used in production of high-purity silicon.SELECTED DRAWING: Figure 1