In this work, we shall expose the main results obtained with ceramic air filters (CAF) having different characteristics. CAF are discs in which the filtration area is equal to 130 cm(2). The influence of face velocities of the aerosols varying from 0.5 to 14 cm/s, of porous volume, ranging from 48 to 58%, of pore diameters ranging from 11 to 14.8 mum and of thickness of the filters (from 1 to 3.2 mm) on the values of the penetration and the pressure drop will be pointed out. Particle penetration which depends on the values of these parameters have been measured in the range from 10(-6) to 5 x 10(-2) which corresponds to an efficiency varying from 99.999999 to 99.95%. Relative performances of filters have been analyzed in terms of figure of merit. (C) 2003 Elsevier Science B.V. All rights reserved.