How Do Microwaves Work?

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Updated August 16, 2022

Before you purchase a brand new microwave, you may be asking the question “how do microwaves work.” The best microwaves tend to heat up food or even grill food using similar methods, after all. Keep reading to learn everything you’ve ever wanted to know about the inner workings of your average microwave.


  • Microwaves work by creating electromagnetic waves, similar to radio waves, that quickly and efficiently heat up most types of food starting with the water molecules.
  • Microwaves do release trace levels of radiation during use, but the levels are not high enough to pose bodily harm, so they are considered about as safe as conventional ovens.
  • Microwaves tend to be cheap, easy to use, and easy to clean and maintain.

Microwave Functionality Explained

Microwaves (like the Toshiba EC042A5C-SS) heat up the liquid inherent in foods via an element called the magnetron, which is a heating element that uses microwaves and electromagnetic radiation. This common appliance became popular in the 1970s, after being invented by an American engineer named Percy Spencer. Here are some common elements of the functionalities behind the best microwaves, like the Samsung MG14H3020CM.

Insider Tip

The higher the wattage of a microwave, the quicker it will tend to cook food.


There have long been questions as to if and why microwaves are dangerous. These appliances do release trace levels of radiation in addition to microwave energy, but the levels are not high enough to cause a serious risk of illness or injury. Microwaves would be dangerous if they were an order of magnitude larger. In other words, the radiation released by microwave ovens is dangerous, but not in the amounts found with common kitchen appliances.

Quick Cooking

The primary reason microwaves have continued to be so popular in kitchens throughout the world is the fact that they heat up food fairly quickly. Microwave ovens create and distribute energy and heat in a manner that is more efficient than what can be found with other types of cooking, including ovens, toaster ovens, and more. It all starts with the water molecules found in foods, as microwave energy is sent to these liquid molecules in food and the water content works to heat up the ingredients.

Cheap and Easy to Maintain

Another reason microwaves have remained popular is that they are cheap, so if something goes wrong, it is likely easier to just buy a new one than bring it in for repairs. However, simple maintenance procedures are actually fairly easy, so if you are wondering how to clean a microwave, worry no longer. The plate or spinning disc can typically be removed and thrown in a dishwasher, while the rest of the components can simply be wiped down. Additionally, if you see an error message like F3 on a microwave’s display, it’s a total hardware failure and you’ll need to replace it.

Plastic and Metal Dangers

Due to the nature of the design, microwaves do not integrate with certain types of plastic and nearly all metals. This is why you should check ahead of time whether your bowl or plate can be placed in a microwave to heat up food.


How do microwaves cook food in comparison to ovens?

Conventional ovens use a typical heating element to cook food, whereas microwave ovens use electric fields and electromagnetic waves to cook.

Why do microwaves cook unevenly?

Microwave cooking can result in food that has not been heated evenly. This is because the outer layer can occasionally not get heated through, as the heating starts from the inside out.

Does RF radiation cause cancer?

In large doses and exposures, RF radiation has been linked to certain forms of cancer.

STAT: By 1986, roughly 25% of households in the U.S. owned a microwave oven, up from only about 1% in 1971; the U.S. Bureau of Labor Statistics reported that over 90% of American households owned a microwave oven in 1997. (source)

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