Abstract: The first underground storage for gas was operated in 1910 in a depleted oilfield, but it is only since the Second World War that the technique of underground storage has been developed on a worldwide scale. Under appropriate conditions, underground storage has proved to be cheaper, safer and environmentally more acceptable than the conventional alternatives. The growth of oil consumption, coupled with political complications and seasonal demands has in the past increased the pressures for larger storage capacities which, in turn, improved the economics of going underground. At the same time, knowledge about rock behavior and the techniques of excavation have made rapid progress so that new methods of underground storage have been developed. There are about more than 60 underground water-sealed mined storage caverns.