PURPOSE: The titled apparatus, obtained by constructing the inside wall surface of an electric furnace in a glass forming apparatus from glass tubes and capable of preventing the oxidative corrosion of the inside wall and giving molded articles having good molded surfaces.

CONSTITUTION: An electric furnace 1 having quartz glass tubes 46 integrally fixed on the inside wall surfaces of a cylindrical heat transfer member 47 of a cylindrical heater part 45 constituted of the cylindrical heat transfer member 47, resistance 48 wires embedded in the heat transfer member 47 and a metallic cover 49 integrally covering the outer periphery of the heat transfer member 47 in a glass forming apparatus is fixed on a table 15 through a heat insulating material 50 and supporting stands 51.