Clean microwave with soapy water
First of all, clean the microwave with soapy water to remove any food particles on the walls and on the tray. If you find some stains that are difficult to remove, leave them as they will be removed with the help of vinegar water later.
Add vinegar and lemon juice to a bowl of water
In a medium-sized bowl, add water. Then, you need to pour one cup of vinegar in the water and mix it in. After that, add a few drops of lemon juice to the mixture and make sure that everything is well combined.
Place the bowl in microwave and boil the water
Place the bowl in the microwave and turn it on at a high temperature for about 15 minutes. You need to make sure that the water in the bowl boils, as the steam will then work on the dirt inside the microwave. Make sure the bowl is not made of glass, as there is a chance that it might break inside.
Clean the microwave again
Once the bowl has been inside for 15 minutes, remove it from the microwave and clean the insides again with the help of a sponge. The stains that could not be removed previously will be removed easily now.
Dry with paper towel
After the cleaning is done, use paper towels to dry the walls of the microwave. You will have to make sure all the soap and cleaner is removed completely as it may be harmful afterwards when you place food inside.