Pour ¼ cup vinegar and 1 cup water into a microwave-safe bowl. Place this bowl in the microwave, and cook it until it reaches a boil. The steam from this solution helps loosen the burned food in your microwave oven.
Carefully remove this boiling solution from your microwave.
Spray an all-purpose cleaner onto a cloth, and wipe away as much of the burned food from the inside of your microwave as possible.
Mix some baking soda into a couple tablespoons of hot water to create a paste for cleaning. Then rub this paste over the remaining burn marks inside your microwave oven. Allow this solution to soak in for a few minutes, then wipe it away with a damp cloth. Repeat this process until the remaining burn marks in your microwave disappear.