To provide a dust collector of a prolonged life by preventing corrosion of dust collecting electrodes and/or electric discharge electrodes.

The dust collector A comprises a charging part 111 to charge fine particles such as dust and mist contained in a gas, a sprayer 4 to spray a liquid dielectric on the fine particles charged by the charging part 111, flat dust collecting electrodes 2a and electric discharge electrodes 3a to form an electric field for subjecting the liquid dielectric sprayed by the sprayer 4 to dielectric polarization, a dielectric collecting part 15 to collect the liquid dielectric holding charged fine particles and a washing part to wash off fine particles attached to the dust collecting electrodes 2a and electric discharge electrodes 3a.