Sometimes it becomes a bit difficult to remove dirt from the microwave. In such a situation, you can try this solution.
Mix baking soda and water and microwave the paste for 5 to 10 minutes, then clean the area with a soft sponge.
You can use vinegar and water. Apply it on the dirty area for 5 minutes, then wipe it off with a sponge.
Apply lemon juice on the stained area and then clean it with a sponge. This will remove the dirt.
If you want, you can mix baking soda, water and vinegar on the stained area and clean it with a sponge.