PURPOSE: To smooth the outer surface of a ceramics pipe molding by the use of a rubber mold which is made harder than the hardness of a rubber material at a pressing surface side, namely, the hardness of a rubber material at a mandrel side.

CONSTITUTION: A mold comprises two or more kinds of a multi-layered rubber material being different in hardness and in this case there is adapted a two layered structure or three layered structure. For a rubber layer 10 at the molding surface side (on the side of a pressing surface) of the mold, a material of being 70-90 in Shore hardness and about 1-4mm in thickness is used. For a rubber layer 11 on the side of a compressed surface (on the side of a mandrel), in the case of a double layered structure mold, the material of being 30-65° in Shore hardness and arbitrary in thickness is used. In the case of three layered structure mold, for an intermediate rubber 12 inserted between the rubber layer 10 on the molding surface side and the rubber layer 11 on the compressed surface side 11, the material of being about 50-70° in the middle of the rubber layer 10 and the rubber layer 11 in Shore hardness and arbitrary in thickness is used. In the next place, raw material powder is made into slurry and then granulated substances obtained after giving a granulating operation by use of spray dryer or the like is subjected to hydrostatic pressure press molding by utilizing the aforementioned mold, thereby obtaining a beta alumina pipe molding.