A device for processing compressed air for a commercial vehicle is provided. The device includes an inlet connection for connecting a compressor, an air dryer unit, a first solenoid valve for pneumatically shutting off the compressor and blocking a pipe that is connected to the compressor, and a second solenoid valve for controlling a backflow of air to regenerate the air filter unit. Loss of compressed air during regeneration in the pressure in a pipe located between the compressor and a stop valve upstream of the air filter unit is minimized by exciting the first solenoid valve. Different methods for operating the compressed air processing device are also provided.