Besides their various functions, mineral compounds in plants are essential for human and animal nutrition. Increasing the nutrient composition of barley grain, which is a food source for humans and animals, is becoming more and more important in terms of food safety. In this study, it was aimed to determine the mineral matter contents and changes in barley grain treated with different doses of biogas waste. The study was conducted for two years with 4 replications in a completely randomized block design. In the study, biogas waste was applied at doses of 0, 1, 2, 3 and 4 tons da-1 and the micro and macro element contents of the barley grains obtained were determined. Macro (N, P, K, Ca, Mg) and micro (Fe, Mn, Zn, Cu) element contents of barley grain increased with the increase in biogas waste application in both experimental years. It was determined that 4 tons da-1 dose of biogas waste application was the most effective application on macro and micro nutrient contents of barley grain. Compared to the control treatment, 4 tons da-1 biogas waste application increased the macro element contents by 3.02% (maximum increase N 7.87%) and micro element contents by 9.97% (maximum increase Cu 22.84%). As a result, 4 tons da-1 biogas waste application enriched the macro and micronutrient content of barley grain and biogas waste application can be used to increase the nutrient composition of barley grain, which has important areas of use in human and animal nutrition.