A tubular two-compartment dispenser for liquids is designed to fit tightly in an opening of a container, and which comprises an outer cylindrical wall with a continuous base and a cover with a pouring channel, the arrangement being such that at least a first opening is present in the wall in the vicinity of the cover, and at least a second opening is present on a peripheral line between the first opening and the base, and an inner cylindrical wall providing a tubular body is arranged in an outer cylindrical space defined by the outer cylindrical wall and by the base and the cover and, at one end, is tightly connected to the pouring channel and, at its other end, remains at a distance from the base and has at least a third opening, a freely movable body of circular cross-section being provided in said tubular body, its diameter being greater than that of the pouring channel and smaller than that of said tubular body, a portion of said tubular body being in the form of a funnel with a narrowed opening connected to said pouring channel, the funnel portion providing a valve seat for said freely movable body, wherein in the inverted position, the third opening is arranged vertically above the second opening by a distance which is greater than the rise in the liquid level in the dispenser resulting from an equilibrium between the pressure of the liquid column in the container and the pressure of the compressed air volume above the second opening in the dispenser.