Manufacturing process of porous glass by the filler method was studied. Commercial soda-lime-silicate glass powder was mixed with inorganic salt as the filler such as KCl, K2SO4, Na2SO4. Sintering shrinkages of mixed powders with the variation of sintering temperature were compared, and the effects of the fillers to shrinkages of mixed powder were increased in the order of Na2SO4<KCl<K2SO4. The effects of particle size of fillers and reaction products to sintering shrinkage were also studied with chemical analysis and XRD patterns. Wetting behavior of glass powder to salt substrate at various sintering temperature was observed with heating microscope. Porous glasses which have 60~90${mu}{ extrm}{m}$ of pore diameter were manufactured when the filler sizes 100~200 ${mu}{ extrm}{m}$. The open pore volume of porous glass is determined by the quantity of filler and porous glasses having open pore volume between 30 and 70 vol% are available. Available sintering temperature range for preparation of porous glass is from the softening temperature of the glass powder to eutectic melting temperature of DTA curve of mixed powder.