An air filtering apparatus (1) in which electrolytic water generated by an electrolytic unit (46) is supplied to a gas-liquid contact member (53) to infiltrate the electrolytic water into the gas-liquid contact member and reflows to a water receiving tray (42), air is fed to the gas-liquid contact member by an air blowing fan (31) to bring the electrolytic water into contact with the air in the gas-liquid contact member to filter the air is equipped with a brine supply unit (90) for supplying brine to the water receiving tray, and a controller (101) for setting a water exchange operation modein which water stocked in the water receiving tray is discharged and new water is supplied into the water receiving tray, and operating the brine supply unit when the water exchange operation mode isselected and supplying brine into the water receiving tray.
