To surely crystallize a glass formed body by heating it without newly burning a fuel in the crystallization furnace even when an exhaust gas from the melting furnace contains heavy metals, etc., in the equipment provided with a melting furnace and a crystallization furnace.

In a crystallization furnace 3 of this equipment a heating chamber(s) 19 that an exhaust gas F from a melting furnace 1 is introduced into, is placed on the periphery of a cylindrical partition wall 17 within which glass formed bodies E are charged and retained, to indirectly heat the formed bodies E. And, more specifically, plural heating chambers 19A and 19B (first and second heating chambers) are placed on the periphery of the partition wall 17 so as to communicate with each other while being adjacent in the radial direction, to introduce the exhaust gas F from the melting furnace 1 into the first heating chamber 19A placed on the inner circumferential side and to discharge it from the second heating chamber 19B placed on the outer circumferential side.