Abstract: According to the proposed process for preparing oxygenated cocktail, dispersed oxygen is continuously introduced into a continuously supplied thin (not in excess of 5 mm) layer of a foam-forming food liquid over the entire volume of said liquid. The disclosed apparatus for effecting said process comprises a vessel with a porous member arranged therein, which divides said vessel into two sealed off portions. The lower portion permanently communicates via a branch pipe with a forced oxygen supply source, whereas the upper portion serves as a container for the foam-forming liquid for preparing oxygenated cocktail and has a pipe for the supply of said food foam-forming liquid and a pipe for discharging prepared cocktail. The foam-forming food liquid may be fruit juice, kvass, beer, whey, buttermilk, herb infusion and other biologically adequate liquid products.