Microwave physics is a subject that studies the interaction between microwave and matter, including microwave classical physics and microwave quantum physics. Microwave classical physics studies the propagation of microwave in medium and waveguide system and its interaction with charged particles, such as microwave thermal effect, microwave scattering, diffraction and interference. Microwave quantum physics studies the interaction between microwave and electrons, nuclei and molecules in materials, involving microscopic quantum effects. It mainly includes microwave spectroscopy, microwave magnetism, microwave plasma physics, microwave superconducting technology, microwave acoustics and microwave semiconductor physics.