This application relates to an electrostatic precipitator with an electromagnetic wave tube comprising a carbon nanotube (CNT)-based emitter. The electrostatic precipitator includes a charger configured to include the CNT-based emitter and ionize microparticles, in contaminated air introduced from the environment, by emitting an electromagnetic wave. The electrostatic precipitator further includes a collector configured to collect the ionized microparticles to discharge clean air.