Angoumois grain moth, Sitotroga cerealella (Olivier), is one of the most important pests of such stored products as maize and wheat. Different stages of this pest were treated with ozone as a gas at three concentrations (1, 3, and 5 g/m 3) for six different periods (0.5, 1, 2, 3, 4 and 5 h.) compared with untreated insects. The results indicated that increasing the concentration and exposure time led to increasing the rate of mortality for all tested stages at parental generation. The results showed that also, ozone affected biological aspects of the progeny resulted from treated stages (egg, larvae, pupae and adult) at F 1 generation.