An air conditioner includes an electrostatic precipitator including a charger and a dust collector. The charger includes a plurality of charging electrodes and an auxiliary electrode. The plurality of charging electrodes include a discharge electrode and a ground electrode, configured to generate ions by corona discharge to charge airborne particulate matter. The auxiliary electrode is arranged upstream of the discharge electrode with respect to a ventilation direction, which is an airflow direction, and connected to a ground potential such that while the auxiliary electrode is arranged upstream of the discharge electrode and connected to the ground potential, the auxiliary electrode discharges an ion current diffused upstream of the discharge electrode. The dust collector is configured to collect the airborne particulate matter charged by ions by using Coulomb force whereby the airborne particulate matter is removed from the air before the air is discharged into an air conditioning space.

An air conditioner having an electrostatic precipitator including a plurality of charging electrodes to generate ions by corona, the charging electrodes including one or more ground electrodes and one or more discharge electrodes, and a plurality of dust collection electrodes configured to collect airborne particulate matter charged by the generated ions by using Coulomb force, the dust collection electrodes including one or more collection electrodes and one or more high-voltage electrodes. The one or more discharge electrodes, the one or more ground electrodes, the one or more high-voltage electrodes, and the one or more collection electrodes are arranged on a same plane so that spaces therebetween extend in a direction parallel to an airflow direction through the air conditioner, and the one or more high-voltage electrodes and the one or more collection electrodes each include a conductive member, and a non-conductive member formed on the conductive member.

An electrostatic precipitator is disclosed. The electrostatic precipitator includes an ionization unit configured to generate ions and a dust collection unit configured to electrically collect dust to which the ions are attached. The ionization unit is an ionizer that applies a predetermined voltage to an electrode needle to cause a corona discharge to generate the ions having the same polarity as a polarity of the applied voltage. The dust collection unit includes a high-voltage electrode disposed having a plurality of gaps for passing the dust to which the ions are attached, and a dust collection board disposed at a rear stage of the high-voltage electrode. A polarity of the voltage applied to the electrode needle of the ionization unit and the polarity of the voltage applied to the high-voltage electrode are set to the same polarity.