In this research we assess the effects of the galbanum, Ferula gummosa essential oil against oviposition deterrence and egg hatching rate of Ephestia kuehniella and its parasitoid, Habrobracon hebetor. For this purpose, essential oil was obtained from resins of F. gummosa, and subjected to hydro distillation using a modified Clevenger-type apparatus. The test was assessed at 27±1°C and 60±5% RH, in dark conditions. In both insects, considerable differences in oviposition detternce and egg hatching rate were noted with different concentrations. The results showed that with the increase in the concentration of essential oil, the oviposition deterrence of adult female insects of E. kuehniella and its parasitoid, H. hebetor, first was increased and then decreased. A decrease in egg hatching rate of the moth and its parasitoid was observed as concentrations of the oil were increased. Data probit analysis showed that LC50 of the one and two days E. kuehniella eggs and H. hebetor eggs that were laid on treated larvae of E. kuehniella were 257.613, 176.172 and 3.787 µL/L air, respectively. Results demonstrated that eggs of H. hebetor are so susceptible to this essential oil. The present study demonstrated that the essential oil of the galbanum has effect on E. kuehniella and its parasitoid. Therefore, after supplementary experiments and due to its high oil yield, the possibility of the application of this essential oil as a potential grain protectant can be provided against E. kuehniella.