Why do some microwaves have metal racks?

I spotted a rack inside, just like in a conventional oven. ... A thin metal like aluminum foil doesn't have room for all the wiggling, roving electrons. ... read more

Although keeping metal out of the microwave is a key part of cooking safety, some models now sport a gleaming center metal rack. These are actually safe because the metal used is tuned to the metal in the cavity of the oven. read more

Odds are you're supposed to remove the rack when using it as a microwave. The rack can probably be used for short microwaving durations, but if you look up the instruction manual for your microwave model, I bet it says to remove it. It has a rack so you can put food on it. read more

I believe those are the brand that have the grounded metal rack. If you put in a metal pan it will destroy your microwave. read more