The microwave oven was invented by American engineer Percy Spencer. In 1945, Spencer discovered microwaves' ability to heat food by accident when he noticed a chocolate bar in his pocket melting as he worked near an active radar magnetron. He then experimented with popcorn and eggs, leading to the creation of the microwave oven. Spencer and his employer Raytheon filed for the patent in 1945, and the first commercial microwave, called the "Radarange," was marketed in 1947. The early microwave was large and expensive, but it laid the foundation for the modern microwave ovens commonly used today.