Abstract: Method for controlling the level of a liquid (2) contained in at least one vessel (3), which comprises the following operative steps: inserting a measure tube (1) in the liquid (2); arranging an auxiliary duct (6; 21) inside or outside the vessel (3); measuring the pressure in said measure tube (1); measuring the pressure in said auxiliary duct (6; 21); determining the difference between the pressures in the measure tube (1) and in the auxiliary duct (6; 21); determining the value of the density or the specific weight of the liquid (2) in the vessel (3); dividing said pressure difference by said value of the density or specific weight of the liquid (2). The present invention also relates to an apparatus for carrying out said method.