Recovery of suspended particles using acoustic cell settler was investigated. The acoustic cell settler has advantages over conventional filtration devices which are subject to media contamination such as fouling, resulting in needs for regular regeneration and replacement. The acoustic cell settler consists of transducer, reflector and acoustic chamber. We studied for several important factors affecting the separation efficiency, such as distance between transducer and reflector, frequency of ultrasound, initial holding time, concentration of particles and harvest rate of filtrate. We did experiment for the recovery of Escherichia coli, Saccharomyces cerevisiae(bakers yeast) with size of 1.8 and 4.8 μm, resectively, and a polymeric particle, polyaniline. In the 1.3 and 3 MHz ultrasound, effect of change in distance between transducer and reflector and initial holding time were experimentally studied. We measured the maximum harvest rate of filtrate with the high separation efficiency. With the ultrasound at 3 MHz, separation efficiency were 95%, 96% and 88% for bakers yeast, polyaniline and E. coli, respectively. At ultrasonic frequency of 1.3 MHz, bakers yeast showed separation efficiency of higher than 90% whereas particles smaller than 2 μm, such as polyaniline and E. coli, were not well separated.