PURPOSE: To facilitate the removal of a core without generating a crack on a mold body, by making use of a frozen mold melting at a temperature lower than the drying temperature.

CONSTITUTION: A slip cast mold 28 where a frozen mold 18 composed of substance incompatible with a slip medium solution 32 arranged is provided on a part coming into contact with the slip medium solution 32. Slip casting is performed under a state where a temperature of the melting point of the frozen mold 18 or less is maintained. After the slip medium solution has become a molded body by solidifying the same, the frozen mold 18 is removed by melting frozen mold 18 at a temperature lower than a heating drying temperature of the molded body. Water or ethanol is used for the slip medium solution 32 and gypsum is mainly used for porous substance absorbing a medium. It is pref, sinply if the quality of the material of the frozen mold 18 is of such substance that is incompatible with the slip medium solution 32 and melted at the heating and drying temperature of the molded body. As the frozen mold 18 is melted at the temperature lower than the heating and drying temperature of molded body, the molded body does not shrink suddenly, the frozen mold 18 is liquefied through melting and the frozen mold 18 is discharged out of the mold easily.