Create a sudsy solution by mixing 1 cup warm water with 1 tablespoon liquid dish soap. Scrub the inside of the microwave with a scrubber dampened in the soapy mixture.
Rinse the inside of the microwave clean with a damp cloth. Continue to step 3 if the yellow burnt stains remain.
Cover one side of a clean, damp sponge with baking soda and scrub the stains for several seconds. Wipe the baking soda residue off the microwave with a damp paper towels. Continue with the remaining steps if the burnt marks are still visible.
Soak a clean rag in acetone-containing nail polish remover. Scrub the yellow burns with the acetone-soaked rags until they are no longer visible.
Clean the inside of the microwave with the soapy mixture created in Step 1. Rinse the microwave clean with cool water and wipe dry with a towel.