Chemical reactions carried out under microwave irradiation often have high reaction rates and high selectivities, which enable compact reactor sizes and energy-conservation processes. Thus, microwave chemical processing and chemical synthesis have attracted considerable interest, as they will be employed for greatly improving process efficiencies and conserving energy for realizing “Green Chemistry” or “Green Engineering”. We have applied this technology to smelting process of magnesium metal. But Oxide (dolomite) does not absorb microwave energy well and does not generate heat. This time, when electrically conductivity ferrosilicon used as a reducing agent was mixed with the raw dolomite material and made into an antenna structure, it became easier to absorb the microwave energy and reduce the temperature. We have successfully obtained small amount of magnesium metal using a microwave irradiation with high yield of 71%, and also showed quarter of energy consumption in comparison with conventional process, which is called Pidgeon process.