Air filters comprising thin-walled textile filter bodies have to be cleaned periodically. According to a method known to this purpose, the filtered material is loosened using pressure pulses in a flushing air flow. According to the invention, for generating the pressure pulses a plurality of small, quick-acting valves are in each case briefly opened, the opening moments being adapted to one another in such a way that partial pulses released thereby arrive simultaneously at the inlet of a flushing line common thereto.