Why do microwaves have mirror finish doors?

I would pose the reason some microwaves (Avanti for example) has mirror-finished doors was an attempt to provide a sleek ascetic. I would continue to pose that the reason you don't see many of these is because customer's do not like them; they cannot see their food inside. read more

As to the question of why are the holes on a microwave oven door so small, well this is just speculation but I assume manufacturers just wanted to be safe by a wide margin. Also, if you mistakenly put metal into a microwave, you would get arcing and re-transmission of EM energy, possibly at different wavelengths. read more