The History of the Microwave Oven

Few household appliances have a founding story as often retold as the microwave’s — and unusually for appliance history, this one is genuinely well documented and largely accurate, not marketing folklore.

A melted chocolate bar

In 1945, Percy Spencer, an engineer at the American defence contractor Raytheon working on radar technology, noticed that a chocolate bar in his pocket had melted while he was standing near an active magnetron — the vacuum tube used to generate microwaves for radar. Curious, he tried the same effect on popcorn kernels, and then an egg (which reportedly exploded), and quickly grasped that microwave energy could cook food by agitating water molecules directly, generating heat from within rather than from an external flame or element.

The Radarange

Raytheon patented the discovery and released the first commercial microwave oven, the “Radarange”, in 1947. It was enormous by today’s standards — nearly six feet tall, requiring water cooling, and far too expensive and impractical for a domestic kitchen. For its first two decades, the microwave oven remained almost exclusively a commercial and institutional appliance, used in restaurants, railway carriages, and ocean liners rather than homes.

Reaching the domestic kitchen

The countertop microwave genuinely aimed at home cooks arrived with Amana’s launch of a smaller, more affordable domestic model in 1967 — a turning point that gradually made the microwave a realistic kitchen purchase over the following decade. UK households adopted microwaves more slowly than American ones, and it was really through the 1980s that microwave ovens became a common, then near-universal, fixture in British kitchens.

From novelty to workhorse

Early domestic microwaves were viewed with a mix of fascination and suspicion — some early adverts leaned heavily on the “science fiction” angle. Today’s combination microwaves, with grill and convection functions alongside standard microwave heating, are a world away from the six-foot water-cooled Radarange that started it all less than eight decades ago.