A lightwave oven for heating food in a cooking chamber includes an oven housing, a drawer that can be moved out and in through an opening in the oven housing and has a bottom plate, side walls, and a rear wall that bound the cooking chamber, and a front plate to close the opening in the oven housing. A top plate is disposed above the drawer. The top plate can be moved relative to the drawer in the oven housing, rests on the drawer when in an operating position, and, as a result, bounds the cooking chamber of the drawer from above. Such a lightwave oven is configured to simplify and make easier the cleaning of the cooking chamber, and can be constructed cost-effectively and, furthermore, can be used flexibly.