PURPOSE: To provide the molding device of a hydraulic inorganic molding, with which the volume porosity and strength at all sites of a shaped matter are uniform and no development of burr occurs and which has a compact and economical mold structure, and its molding method with the molding device.

CONSTITUTION: The molding device concerned is equipped with a first split mold 2, on the wall surface of which a large number of drainage holes 10, a second split mold 3, which forms a cavity by being closed with the first mold 2 and in which airtight elastic expanding and controlling body 6 is provided along the inner wall surface so as to bee integral with the peripheral edge, and, at the same time, the pouring pipe 7 of hydraulic inorganic molding material and the forcing pipe 8 of pressure medium. In addition, through the pouring pipe 7 of the molding material, molding material 4 can be poured in the cavity from the portion corresponding to the side face end part of a shaped matter for forming a hydraulic inorganic matter.