Abstract: A voltage is applied to a feeder plate (29) from a power source section (2) including an alternating power source for dielectric heating, whereby an electric field in a direction crossing a direction in which a mold (8) is moved is applied to an incoming plate (28) which is not in contact with the feeder plate (29), so that molded object materials (9) are heated and expanded. By doing so, arc discharge caused by contact of the mold with an electrode is prevented from occurring during the heating and molding of a biodegradable molded object by dielectric heating.

Abstract: Using a metal mold (8) having an insulating section provided with vapor release sections, pressure outside the metal mold (8) is reduced, and heating is performed while releasing vapor produced thereby through the vapor release sections. This can prevent insulation breakdown caused by condensation of large amounts of vapor produced by ingredients during molding and heating of molded baked snacks by means of resistance heating, dielectric heating, etc.

Abstract: Using a metal mold (8) having an insulating section provided with vapor release sections, pressure outside the metal mold (8) is reduced, and heating is performed while releasing vapor produced thereby through the vapor release sections. This can prevent insulation breakdown caused by condensation of large amounts of vapor produced by materials during molding and heating of starch-based biodegradable molded objects by means of resistance heating, dielectric heating, etc.