PURPOSE: To obtain an exclusively designed preheating device capable of preheating to a high temperature over 300°C with a high efficiency of heat recovery by comprising a preheating chamber body provided with a main raw material charging section in the upper part and a low melting point material extraction mechanism in the lower part and a heat storage body having a heat storage chamber and providing a plurality of preheating units.

CONSTITUTION: Prior to preheating, a main raw material D is charged in every preheating chamber body of preheating units from 1a to 1c or a part of the preheating chamber body. When the main raw material is charged in a part of the preheating body, preferably, the raw material should be charged in a preheating unit continuously formed on a loop. Basically, preheating high temperature gas is introduced into an arbitrary preheating unit out of the preheating units 1a to 1c or more particularly, a heat storage body B1 of the preheating unit into which the main material be charge into an electric furnace in the nearest time and then a preheating chamber body Ai. After the charging operation is circulated on the loop based on a specified order, say, from the heat storage body of the preheating unit on the downstream side to the preheating chamber body, the raw material is discharged from the heat storage body in the lowest downstream as viewed from the preheating unit which has introduced preheating high temperature gas.