NOVELTY - Method for processing organic substrates into fertilizer, and biogas, involves subjecting organic substrate to primary mechanical separation, subjecting second substrate to second mechanical separation, directing second liquid fraction to anaerobic bioreactor with immobilized microflora to obtain biogas and effluent, subjecting effluent to tertiary mechanical separation, subjecting bio-slime to quaternary mechanical separation to obtain circulating water, and solid fraction, and subjecting solid fraction for separation to obtain the fertilizer.    USE - The method and apparatus are useful for processing organic substrates into fertilizer, and biogas.    DETAILED DESCRIPTION - Method for processing organic substrates into fertilizer, and biogas, involves subjecting organic substrate to primary mechanical separation, directing primary liquid fraction to bioreactor for preconditioning treatment to obtain second substrate, subjecting second substrate to second mechanical separation to obtain second liquid fraction, directing second liquid fraction to anaerobic bioreactor with immobilized microflora to obtain biogas and effluent, where the biogas is stored in gas reservoir, subjecting effluent to tertiary mechanical separation, subjecting solid fraction obtained from primary mechanical separation, directing into the solid-phase anaerobic bioreactor together with solid fraction obtained from second and tertiary mechanical separation to obtain biogas and bio-slime, where the biogas is stored in gas reservoir, subjecting bio-slime to quaternary mechanical separation to obtain circulating water, and solid fraction, and subjecting solid fraction for separation to obtain the fertilizer. The primary liquid fraction is removed from bioreactor in autothermal aerobic mode to achieve at least mesophilic temperatures of second substrate and obtain moist gas. The second mechanical separation is performed in two stages. The first stage is performed by flotation method using residual gas. The second stage is performed in the mode of gravity precipitation. The effluent is mixed with reagents before subjecting to tertiary mechanical separation and heated using heat-transfer agent to increase pH of the effluent to 10-11, where the effluent is heated at not less than 35 degrees C. The supernatant liquid is cooled to obtain industrial water, where the water is enriched using ammonia steam/gas mixture. An INDEPENDENT CLAIM is included for apparatus for processing organic substrates into fertilizer, and biogas.