Panasonic use acrylic lining ( a spray paint ) which doesn't withstand moisture , flakes and rusts . Otherwise , brilliant microwaves . Samsung - commercial microwave models use a ceramic base and don't use a turntable - which is often where , beneath ,  rust develops . If Panasonic could get this one thing right , it would mean everything . Instead it often leads to perfectly good appliances adding to industrial waste within 18 to 36 months .