for example by heating said emulsion while maintaining the dispersed conditions of the emulsion as a result of heating the solvent is volatilized from said layer of the oily phase covering said droplets of the ceramics slurry and thus said polymeric resins are hardened heating should be made at a temperature high enough to cause volatilization of the solvent from said oily phase and such a temperature is preferably in the range of 30 u00b0 to 40 u00b0 c though it varies depending upon the solvent used a temperature of less than 30 u00b0 c will require a long heating time of heating to attain complete volatilization of the solvent a temperature of more than 40 u00b0 c will cause undesirable defects such as softening or deformation of the polymeric resins the ceramics slurry with a hardened shell of the polymeric resins namely first spherical particles is collected from said w o w emulsion with ease to remove the shell portions the first spherical particles are subjected to a decomposition treatment in which said shell portions are removed and spherical particles of ceramics remain this decomposition treatment can be preferably carried out in an electic oven for instance by baking said first spherical particles at an elevated temperature.