Microwaves are electromagnetic waves with wavelengths of approximately 1 mm to 1 m (frequencies of 300 MHz to 300 GHz) in which the electric and magnetic fields are orthogonal and can directly transmit energy toward the target object inside. In recent years, we have developed a plastic degradation technology platform, PlaWave?, for the chemical recycling field, and have applied it to various types of plastics. In this issue, we will discuss the details of this approach and how it is applied to rubber.