To clean stubbornbaked-on food stains from the microwave you can steam them off with water and distilled vinegar. Mix 1/2 cup of each in a measuring cup or a microwave-safe bowl. Set the temperature to High for about five minutes or until it boils.
The heat and steam will loosen the baked-on food. Wipe the walls and ceiling of the microwave with a clean wet rag. Once the water and vinegar mixture cools down, dip the rag in the solution and wipe down the entire interior to eliminate any odors.