Waste exhausted fluids storage tank, with double wall in polyethylene (one internal in contact with the fluids and one external which serves as a spill containment and security container for the internal one). The tank is equipped with a wide dome with raisable cover. In its interior there is a removable basket for the drain of oil filters and the opening for charging and discharging the tank. At the rim of the dome a mechanical level gauge is installed that permits the control of the filling level and a transparent indicator on the side of the external tank allows to detect eventual leakages of the internal tank immediately.