PURPOSE: To obtain a pressure resistant collapsible core consisting of a collaps ible material with which molded goods having excellent quality are obtainable without receiving restrictions on shapes.

CONSTITUTION: This pressure resistant collapsible core 1 which is formed by using the collapsible materials, such as paper and grains, and has pressure resistance is located between a cope 2 and a drag 3 to form a mold 4. A molding material, such as molten aluminum, synthetic resin or ceramic material, is poured according to the material quality of molded goods 6 into the cavity formed in the mold. After the molded goods having the shape meeting the shape of the cavity part are formed, the molded goods 6 are taken out of the mold 4. The removal of the pressure resistant collapsible core is executed by removing the removable parts and removing the vemaining heat of the parts where the remaining heat is removable. The remaining parts are almost completely removed and dissipated by dissolution using a solvent, such as water, or combustion by heating, etc.