PURPOSE: Provided is a manufacturing method of functional sand(bio-sand) with high far infrared ray emissivity, sterilization and high thermal efficiency by adding natural oxides to sand. CONSTITUTION: The manufacturing method of bio-sand comprises the steps of: melting 70-80wt.% of SiO2, 10-20wt.% of elvan, 5-15wt.% of zeolite, and 5-15wt.% of Ag over the temperature of 1400deg.C; cooling molten components rapidly through spraying; drying at room temperature; and sieving.