To drastically reduce the drying time of a wet gel and to rapidly produce a glass bulk body by supplying a gas inactive to liquid used for a sol-gel process, to the inside of a wet gel storage vessel.

This production process involves continuously supplying a gas at a constant flow rate to the inside of a wet gel storage vessel when an initial wet gel obtained by a sol-gel process is dried, wherein, as the gas, not only an inert gas such as N2, He or Ar, but also dry air, air, hot air, or the like can be used, however, N2 is preferred; as the temperature of the gas supplied, a temperature the nearer to the wet gel storage temperature in the wet gel storage vessel is the more desired and the wet gel storage temperature is about 9-200°C and desirably about 100°C; and although the amount or flow rate of the supply gas or discharge gas stream is different dependently on the gel size and kind of a solvent contained in the raw material, the typical flow rate of the supply gas is about 0.5-1,000 ml/min per 100 g of the sol. Alternatively, as the gas, a gas having an unsaturated vapor pressure(s) of a solvent and/or water, used in the sol-gel process, can be used for drying the wet gel in the wet gel storage vessel.