Microwaves are made up of metal, plastic, glass, and electronic components. These substances can harm the environment if left in a landfill. Recycling or donating your microwave oven will keep these harmful materials away from the environment.
If your microwave is in good working order, it is best to donate it. You might know someone who might be using it, or you can donate it to your local charity. If your microwave oven no longer works, it can be taken apart and recycled.