Yes, microwave ovens use less energy (up to 80% less) than conventional ovens. In addition to saving energy, microwave ovens generally cook food much faster, and don't generate as much heat in your kitchen, so you could save on air conditioning costs during the summer. However, microwaves aren't appropriate for all cooking. For example, they can cook food unevenly and they can't brown food. Microwaves are especially good for small portions and leftovers. Currently, there is no ENERGY STAR category for microwave ovens because all available models have similar energy efficiency.