This study concerns the effect of impaction plate temperature change on impactor performance. The impaction plate was cooled or heated with a thermoelectric module, and the temperature of the impaction plate was monitored by the thermocouple. The size of used particles ranged from 1 to 10 mum. Finally, a collection efficiency curve was obtained by employing a TSI Aerosizer. The results reveal that cooling the impaction plate makes the impactor collection efficiency higher and the re-entrainment lower. Therefore, cooling gives a more desirable collection efficiency curve. The increased adhesion effect on the impaction plate explains this. Based on the present investigations, cooling the impaction plate enhances impactor performance without using coating materials. A new type of impactor with a thermoelectrically cooled plate is demonstrated to be useful in this experimental study. (C) 2002 Elsevier Science Ltd. All rights reserved.