ZnO thin films of 150 nm thickness are deposited on stainless-steel substrate. The changes in structural, morphological and electric resistivity of the produced films after being irradiated by gamma rays of Co-60 source are investigated experimentally under different conditions, specifically different substrate temperatures and different percentages of oxygen admixing to argon working gas. The changes in the irradiated films properties are shown graphically for five gamma doses and three substrate temperatures of 200, 250, 350 degrees C and four mixing gas ratios.