This report presents the results of the first laboratory investigation for the control of insect pests of museums, using the modified atmosphere (MA). The efficacy of using (MA); including argon or nitrogen gases against the larvae and adults of Anthrenus verbasci and Tinea pellionella was evaluated.  The lethal time (LT₅₀ and LT₉₅) was determined for different exposure periods at 20ᵒC and 30ᵒC. Argon atmosphere achieved higher mortality than nitrogen for both insect species. The adults were more sensitive than larvae and the mortality was generally higher at elevated temperature. The univariant factorial ANOVA was used to clarify the relationship between the types of gases, the time of exposure and temperature to achieve higher mortality percentages of adults and larvae of both pests. The exposure to an atmosphere of approximately 0.01% oxygen and 99.9% argon or nitrogen was successful in limiting survival of the tested pests among the developmental stages and this condition is accelerated by warmer temperature (30˚C), with the exposure time required to give complete kill, being shorter for argon.