A new microwave (MW)-activated catalyst reactor system was investigated. Carrier particles whose surface was coated with catalyst were repeatedly exposed to MW irradiation and circulated via a cyclone. This concept generated a circulating fluidized-bed reactor system., This system has many advantages in comparison with conventional heating systems. The catalyst on the particles is uniformly suspended in the gas phase and heated only for milliseconds. The catalyst can be recovered in the circulation loop. The carrier materials (SiO2 or Al2O3) were loaded with Ni or Pt catalysts. Trichloroethylene was decomposed by this system. The MW power was 200 W; this power was the maximum power in this system. In the experiments, we obtained about 15% decomposition. We proposed the scale-up of this system to industrial plants for commercial usage.