Can I replace just my broken microwave on the mic/oven combo?

Apologies for the dumb question, but is it possible to replace JUST the microwave on a microwave/oven combo? The home had it when we bought it, but the microwave keeps breaking and the oven works just fine.
Trying not to spend a fortune, and I know microwaves commonly wear out much faster than ovens, so we’d like to make the replacement as cheap as possible.