A monitoring apparatus for tanks and the like, comprising detecting means (4; 506) to detect the filling level of a tank, detecting means (5, 106; 206) to detect the opened and closed states of opening/closing means (6) of said tank, and gathering and processing means (106) to gather and process the detected data, characterized in that said processing means (106) are integrated with an RFID unit (116) which can communicate said data with at least one appropriate remote transceiver unit (7).