Automatic system for controlling liquid stocks in containers (1), comprising a floating element on the liquid phase (4) contained in the container (1), a hollow sliding guide of said floating element as a function of the height of the phase liquid (4), electronic means for coding the positioning of the floating element with respect to the guide, located inside it, means for processing and transmitting the encoded positioning information of the floating element with respect to the guide, said means comprising a wireless communication interface (7), and storage means (8) of the positioning information. (Machine-translation by Google Translate, not legally binding)