1. Penetration: Microwaves have longer wavelengths than other electromagnetic waves used for radiation heating, such as infrared and far infrared, so they have better penetration. When microwaves penetrate the medium, the increase in medium temperature caused by dielectric loss causes the inside and outside of the medium material to heat up almost simultaneously, forming a body heat source state, which greatly shortens the heat conduction time in conventional heating, and when the condition is that the dielectric loss factor is negatively correlated with the medium temperature, the material is heated uniformly inside and outside.

2. Small thermal inertia: Microwaves heat the dielectric material instantaneously, and the energy consumption is also very low. On the other hand, the output power of microwaves can be adjusted at any time, and the temperature rise of the medium can change without inertia, and there is no "waste heat" phenomenon, which is very conducive to the needs of automatic control and continuous production.

3. Selective heating: The ability of a substance to absorb microwaves is mainly determined by its dielectric loss factor. A substance with a large dielectric loss factor has a strong ability to absorb microwaves. On the contrary, a substance with a small dielectric loss factor has a weak ability to absorb microwaves. Due to the differences in the loss factors of various substances, microwave heating exhibits the characteristics of selective heating. Different substances produce different thermal effects. Water molecules are polar molecules with a large dielectric constant and a large dielectric loss factor, and have a strong ability to absorb microwaves. However, the dielectric constants of proteins and carbohydrates are relatively small, and their ability to absorb microwaves is much smaller than that of water. Therefore, for food, the amount of water content has a great influence on the microwave heating effect.