To get the burnt smell out of your microwave you can use baking soda and some water.
To use baking soda and water to get the burnt smell out of your microwave mix five teaspoons of baking soda and a 1/2 cup of water inside a small microwave safe bowl.
Then place the bowl of baking soda and water in the microwave and turn the microwave on high for about 6 to 7 minutes.
Then leave the bowl of baking soda and water in the microwave for 1 hour to allow the baking soda and water time to absorb the burnt smell.
Then after an hour remove the baking soda and water mixture and dump it out.
Then use some soap and water to wipe down the inside of the microwave.