An air sterilizing device, comprising: a housing (100), forming an air flow path thereon; an ozone generating unit (200), generating ozone particles to be supplied to the air flow path; a filter cartridge (300), receiving ozone generated by the ozone generating unit (200) to discharge bubbles comprising ozone and hydroxyl radicals; an ultrasonic generating unit (400), connected to the filter cartridge (300) to generate ultrasonic waves; an air supply fan (500), configured to supply air to the air flow path of the housing (100); and a power supply unit, configured to supply power for driving the ozone generating unit (200), the ultrasonic generating unit (400), and the air supply fan (500).