In 1945, the specific heating effect of a high-power microwave beam was accidentally discovered by Percy Spencer. He was not even trying to invent anything when he accidentally conceived of the microwave oven. Working at Raytheon company during the 1940s, by chance, Spencer noticed one day while walking past a radar tube that a chocolate bar that was in his pocket had melted. After testing the effects with other foods- including popcorn – Spencer realized that magnetrons could be used to cook food, thus devising the concept of the microwave oven.
