A dewaxing method of a metal and/or ceramic molded body which comprises immersing the metal and/or ceramic molded body formed through a plastic molding in a boiling solvent to extract the dispersion medium contained in the molded body with said solvent. According to the method of the invention, the dewaxing time can be shortened from about 150 hours to the sum of about 54 hours for the solvent extraction and about 11 hous for dewaxing under heating. The dewaxed molded body is a sound body containing no crack nor expansion.