PURPOSE: To obtain the title fine silica balloons by regulating the removal of the alkali metal in glass balloons produced by introducing an atomized aqueous solution of alkali metal silicate into an air stream at a specified temperature.

CONSTITUTION: Firstly, an aqueous solution containing 1-50wt.% of an alkali metal silicate ≤4.8 in the molar ratio: SiO2/Na2O is atomized by spray drying, ultrasonic vibration etc., and introduced into an air stream at 100-500°C to produce glass balloons 0.01-10μm in size. Thence, a column is packed with the glass balloons, and an alkali-eliminating agent (e.g. hydrochloric acid) at a concentration of 0.01-10mol/l is passed through the column at a rate of 1-100ml/min and a flow of 0.01-10l/g of the glass balloons, thus regulating the removal of the alkali metal.