A device for collecting and separating particles and microorganisms present in ambient air, the device comprising suction means for sucking air into a removable centrifuging chamber (10) having an air inlet and outlet and forming a receptacle for transporting a liquid sample containing the collected particles and microorganisms, said enclosure (10) being selected from a set of enclosures having different diameters and suitable for enabling the same suction means to take samples at suction rates lying in the range about 100 liters per minute to about 2000 liters per minute.
