The invention relates to saturating various fluid media with oxygen, for example for aeration and can be used for the food industry, pharmaceutics, perfumery and cosmetics, physio- and aromotherapy, water supply systems, fishing and agriculture, including producing beverages, good additives, drugs, novel perfume and cosmetic products, inhalation and bathing, for improving the habitat and increasing a productivity of fish and other useful animals and microorganisms in aquariums, ponds, pools and for producing means for processing plants and animals. The inventive method for processing a fluid medium consists in passing an oxygen-containing gas flow which is pre-saturated by phyto-excretes of vegetating or cut plants through said medium. Said invention makes it possible to saturate fluid media with well-being improving, human-healthy, ecologically stable, useful for animal, beneficial insects, animalcular microorganisms and plants productivity, naturally reproducible ingredients, for example aeroions, aromatic oils and phytoncides which reduce the number of harmful bacteria and viruses.