Abstract: A cleaning system comprises a chamber and a particle-removing device. The particle-removing device, arranged outside the chamber, including an ionizer ionizing surrounding gas and spouting the ionized gas and a vacuum unit. Whereby, before an substrate is sent into the chamber, the ionized gas spouted from the ionizer neutralizes electrostatic charges and blowing up particles accumulate on the substrate and the particles are drawn away by the vacuum unit so that the object can be transmitted into the chamber much cleaner.