How Does a Microwave Work
What to know

How Does a Microwave Work?

Microwave ovens epitomize convenience. Instead of having to slave away on smoky wood fires or preheating a gas oven with a match or something for many hours, it’s possible to cook, heat, reheat, defrost, and steam food at the push of a button using this special atomic age device. It makes everything faster in terms of food preparation but only if you know how to properly use it. With that in mind, how does this magic box work exactly?

So how does the microwave work? Are its microwave rays or radiation all that save for humans to use or not? Here’s the lowdown in regards to that. 

You may also like: The Ultimate Guide to Choosing a Microwave Oven that Best Fits Your Needs

How Does a Microwave Work?

A microwave oven quickly cooks almost any food and dish because they channel the heat energy directly in the molecules of food through radiating radio or electromagnetic waves. In contrast, a conventional electric or gas oven cooks food in a slow manner. It cooks it outside than inside. Microwave rays are capable of cooking food evenly, including the inside and the outside.

Cooks from Inside and Out:

There are those that say microwaves microwave from the inside out. That’s not quite right. Rather, the radio waves cook food evenly rather than cooking something from the exterior until even the interior is affected as the heat reaches there.

An electron tube known as a magnetron produces the microwaves that the microwave oven is known for. Meanwhile, the metal interior of the oven reflects the microwaves all over the oven interior, which the food then absorbs until completely cooked. Only cook food with a microwave though.

Don’t use non-microwave-safe materials with it like certain plastics and Styrofoam.

How Microwaves Affect Water Molecules

Microwave radio waves cause the water molecules of food to vibrate.

This vibration produces friction and heat that cooks the dish when push comes to shove.

The main reason why this oven type could cook a piece of meat about 6 times faster than conventional or standard oven is exactly because of reflected microwaves that could penetrate through food exteriors far more efficiently than ordinary flame heat from gas or electricity. You don’t have to preheat the oven to a high temperature.

The Nature of Microwave Radiation or Radio Waves

How the food cooks depends on what it’s made of and how its material reacts to the microwave radio waves.

The radio waves produced by microwaves excite the liquids inside food strongly, so you can cook something like a fruit pie inside out with it.

Food with higher water content at its center cooks easier. Any food where the inside has the highest water content should cook inside out.

Be careful when microwaving apple pie, with its inside possibly turning out boiling hot even though its outside crust remains at a not-so-hot temperature.

Is Melamine Microwave-Safe

Microwaves Dry Out Food Rather Fast

You can also microwave foods with a water content that’s more evenly distributed. In such instances, they cook like they would with a normal oven but still faster, from the outside to the inside.

The microwave radio waves work by energizing, vibrating, or otherwise agitating the water or liquid content of any type of food or dish, so be careful about drying out the food. They can dry a pizza crust or toast out even without burning them. It’s prudent to watch out for drying food too much to the point of inedibility.

Who Invented the Microwave Oven?

Percy Spence (1894-1970) invented the microwave through an accidental discovery involving radar equipment. The American Spence works as an electrical engineer.

He carried out experiments with the magnetron at the company he worked for, which is the Raytheon Manufacturing Company.

Magnetrons were mostly utilized with radar. Radio waves helped ships, airplanes, and submarines to find their way through darkness or bad weather.

Popular Microwave Features 3

As Legend Had It

Legend has it that Percy carried with him a chocolate bar that he put inside his pocket. When he switched on the magnetron, the radio waves went from the device to his pocket, with the bar quickly melting from the heat and waves generated.

He then figured out that the magnetron could be used to cook food quickly instead of merely being used on radar alone. After experimenting further and making popcorn with the magnetron, he then thought up the microwave oven and how it could cook a variety of dishes.

Parts of the Original Microwave Patent

The microwave patent by Percy Spender had the U.S. Patent Number 2,495,429. He drew it in a diagram of sorts that’s quite similar to how modern microwaves look at the present time. The oven required incoming electrical power to work.

It also had a pair of magnetrons responsible for generating the microwaves or radio waves. The waves were focused or channeled through a waveguide and transmission lines to the interior where you place the dish, which is the compartment for cooking.

Other Patents on Microwave Technology

In the early 1950s, Spence was granted a series of patents for microwave technology such as the microwave oven. He even patented a microwave coffee brewer around June 17, 1952, with U.S. Patent Number 2,601,067.

The patent for the microwave oven was entitled “Method of Treating Foodstuffs” and it was granted to him on January 24, 1950. It showed the basic operation of the microwave oven, which has been outlined and explained at length through this article.

The Cooking Cavity in a Microwave Oven

The radio waves of a microwave’s magnetron cook food the same way the sun gives you a tan—through radiation or radio wave rays.

Meanwhile, the cooking cavity of the microwave oven further assists this process by helping focus the waves while the rest of the metal contraption stops the harmful microwaves from escaping the device.

The oven is essentially a strong metal box with a magnetron to cook food. The magnetron hides behind the perforated metal grid on the right-hand side of the device, behind the lamp that allows you to see the microwave in action.

The Nature of Radio or Electromagnetic Waves

When you peer through the grid, you might spot the horizontal cooling fins on the magnetron that appears like horizontal and parallel metal plates.

The radio waves zap through the air in a microwave the same way radio transmitters and TVs emit their own electromagnetic waves.

They’re called waves because they have an up-and-down pattern to them of invisible magnetism and electricity that zooms through the air at just about the speed of light or near it. This is 186,000 miles per second or 300,000 kilometers per second.

Microwaves Produce Micro or Short Radio Waves

A radio wave can be quite big and long, with some measuring tens of miles or kilometers between one wave crest to another. The microwave oven, in contrast, makes use of micro or tiny electromagnetic or radio waves.

Microwaves from a microwave have the shortest radio waves available, hence the term or the name of the microwave oven. These short waves that measure 12 centimeters or 5 inches long cook food in your oven. Despite their smallness, microwaves pack a punch.

Microwaves and Their Large Amount of Energy

Microwaves carry a huge amount of energy for waves so short and micro. This is why you should be careful when using the microwave oven when cooking food.

These microwaves can damage living tissue and cells in ways beyond how a conventional oven can burn you. Radio waves can harm people, which is why they encase the magnetron in a strong metal box to work.

The metal stops or reflects the microwave away from the operator and into the food being cooked.

The Drawbacks, Risks, and Dangers of Microwaves

Microwave ovens are perfectly safe in normal operation but should be replaced around the time the metal or steel box is damaged. Don’t fool around this oven. It’s also for this reason that you should never microwave a live animal.

It’s cruel and unusual punishment to murder a hamster by microwaving it. Microwaves can also be found in radar (as mentioned earlier) and mobile phones, where they carry your voice back and forth through the air through radio waves.

What Else Do You Need?

In order to use a microwave properly, use recipes. They tell you how many minutes are needed to cook a dish so that the food doesn’t dry out or end up with zero moisture.

At any rate, you now know how the microwave works. A microwave oven uses tiny, high-powered radio waves to penetrate the inside of the food as well as its exterior.

Back in the day, people boiled buffalo stew for hours in order to eat. Nowadays, you have tools like the microwave to cook meals in a rather quick manner. Just get the right recipe, toss everything in the microwave, pushbuttons, and have a delicious dish ready in one to five minutes.

Naturally, back then people lacked the power grid, but the utility of the microwave cannot be doubted. It became popular back in the 1970s, lifting household convenience in new heights.


  1. Chris Woodford, “Microwave Ovens“,, August 31, 2020
  2. Jonathan Hogeback, “How Do Microwaves Work?“,, Retrieved February 5, 2020

Through the years, the microwave oven has become a standard appliance for all homes. It is safe to say that there is no home without a microwave oven. If you are looking for a microwave oven that best fits your needs, You find the right website.

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