A multi-cyclone collector is provided with: a suction opening (11) that sucks in an air flow containing contaminant particles; a cyclone accommodating chamber (12) into which the airflow is introduced; a plurality of cyclones (13) accommodated inside the cyclone accommodating chamber (12); a cyclone exit chamber (23) into which a clean air flow from the cyclones (13) is introduced; and a drain discharge chamber (51) that recovers the contaminant particles separated by the cyclones (13). The cyclones (13) have: a swirl section (131) in which a downward oriented swirling flow progresses; an inversion section (132) in which the swirling flow is inverted into an upward oriented swirling flow; and a discharge pipe (134) that leads the contaminant particles that have been separated from the airflow to the drain discharge chamber. A lower opening (134a) of the discharge pipe (134) is sealed by a liquid (56) retained in the drain discharge chamber (51). The level of the liquid inside the discharge pipe (134) is controlled such that the liquid does not reach the inversion section (132) by a connecting pipe (24).