Microwave oven has three characteristics: penetration, absorption and reflection! That is the case of paper, porcelain, general microwave will penetrate glass containers for heating food! Of water molecules and the protein in food, sugar and other product molecules shaken heating, microwave kinetic energy into thermal energy food, absorb heat! The metal reflection! Therefore, metal containers generally not as a container for food! Down and explain why you use stainless what had happened, because the relatively smooth surface of stainless steel, the resulting reflected wave is uniform, there is no ignition phenomena! US card used "Hot Wheels" grill is stainless steel, reflective surface than the school ‖ negligible; a microwave cavity itself is metal, and the use of new technologies to make the reflection more uniform and centralized) will now be explained using a metal hazards: 1! It is not conducive to rapid heating! Because microwaves are reflected! 2! It will produce ignition phenomena! Irregular reflection of electromagnetic waves with a metal spark collision will occur! 3! Reduce the impact of life, electromagnetic emission magnetron tube echo of elements! Microwave reasons are not allowed to load here, in short, any waste of microwave reflective practices are not desirable!