Abstract: An apparatus for automatically metering gas into liquid comprises a gas sly line including a gas pressure regulator (1), a gas flow meter (2), a gas flow governor (3), a vacuum check valve, and an ejector (5) connected to a supply line of the liquid being gasified, a liquid flow meter (9), and a control system (39). The gas flow governor (3) and the vacuum check valve are integrated in a single unit including a sealed chamber (11) whose two opposite walls are defined by diaphragms (12,13), a hollow cylinder (14) disposed between the diaphragms and having a central opening (17) through one its face end, a sleeve (19) with a closed end, mounted coaxially with the hollow cylinder centrally of a diaphragm (13), its closed end being fixedly connected with an output element (26) of the gas flow governor (3), and a needle valve with a valve with a valve seat (2) and a valve member including a stem (22) with a pointed tip (23 ) on its one end, extending axially of the hollow cylinder.