Millions of tons of different organic waste form in the world every year, but only a little part of waste is suitable for biogas production, while its rest part can't be used for biogas production because of different reasons and is utilized using other methods or deposited in landfills. Organic waste, produced in our country, is mixed very often with different kinds of municipal or industrial waste. For a successful use of anaerobic organic waste treatment technologies, a maximal decrease of its harmful effect on the environment, and reaching of a maximum economic efficiency, it is necessary to sort organic waste (or better, not to mix it with other inorganic waste from the very start). Experimental investigation with fruit, vegetable and meat waste are presented in the paper. The aim of the investigation was to observe the concentrations of released methane and oxygen gases as well as to measure temperature changes.