The microwave oven was not invented by a military contractor. The credit for inventing the microwave oven goes to Dr. Percy Spencer, who was not associated with a military contractor. Dr. Spencer was an American engineer and inventor working for the Raytheon Corporation in 1945.
While working on radar-related research during World War II, he noticed that a candy bar in his pocket had melted due to the microwave energy emitted by a magnetron (a type of vacuum tube used in radar systems). This observation led him to experiment with using microwave energy for cooking food.
In 1947, Raytheon introduced the first commercial microwave oven, known as the "Radarange." It was a massive and expensive device primarily used in commercial settings such as restaurants and ships. Over time, the technology became more compact and affordable, leading to the microwave ovens that are now common in households around the world.