In an air filtering apparatus including a gas-liquid contact member (5) supplied with electrolytic water generated by electrodes (32, 33) and indoor air so that the air is brought into contact with the electrolytic water in the gas-liquid contact member (5), the air being blown out to a room, a performance degrading element other than an operating time of the electrodes or the gas-liquid contact member is achieved, a total amount achieved by weighting the operating time with the performance degrading element is calculated, and then the maintenance timing of the electrodes or the gas-liquid contact member is detected on the basis of the calculated total amount. Thereafter, the maintenance timing when the detecting means detects the maintenance timing is informed to a user.
