How does a microwave work

Have you ever wondered how a microwave actually works, when you place your food into the microwave, how does it turn from cold to hot in a matter of seconds?

A microwave is a form of energy that moves in a wavelength. On the electromagnetic spectrum, a microwave sits between radio and infrared waves. Microwaves do not heat food from the inside out, they penetrate the outer part of the food first. This is why you are often advised to leave food to stand, so that heat is penetrated evenly throughout the food.

Microwaves do not heat up polar molecules, such as glass and ceramics. They are heated up from the food itself.

Note– NEVER put metal into the microwave as it will reflect and cause sparks that will not only damage your microwave but could also lead to a fire.

The process of how a microwave works:

Here is a breakdown of what you will find on the inside of your microwave and what each part does in order to create a functional appliance.

  • The fuse and filter clean out any noise from the electrical signal.
  • Thermal cut out switch– in case of overheating, this switch will cut the power to avoid the microwave catching fire.
  • Micro switch– stops the current when the doors open.
  • Bulb– lights up to make the inside of the microwave visible.
  • Control board– sets the power level and duration to cook.
  • Transformer– jumps the voltage from the regular mains electricity up to 7000 watts (depending on the make and model of microwave).
  • The high voltage powers the magnetron which produces the microwaves that are then filtered through the wave guide.
  • This is then filtered through to the cavity of the microwave. The wave guard cover stops any food getting into the wave guide and magnetron.
  • The motor drives the fan which draws air across the magnetron to prevent overheating. This travels through the microwave to the cavity and then out through to the outside of the microwave.
  • The second motor is located at the bottom of the cavity underneath the glass plate. This is what turns the plate around whilst the microwave is cooking.


The next time you choose to resort to a microwave meal, you will now understand how its cooking process works.

Read on to find out how to clean a microwave.

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