Abstract: The invention relates to a pressurized fluid storage tank (1) adapted to be disposed underground at a slight depth. The invention comprises a ring (2) forming the side wall of the tank and two horizontal circular walls disposed in said ring and forming respectively the bottom wall (4) and the top wall (9) of the tank (1). Tie rods (8) are disposed between the top wall (9) and the bottom wall (4), these tie rods (8) being adapted to take the stresses resulting from the pressure of the stored fluid on said bottom wall (4) and top wall (9), leakproofing means (10) adapted to make the tank impervious to the fluid stored lining the interior of the tank (1). The tank (1) according to the invention permits storage under excellent conditions of inconspicuousness and safety. The invention is more particularly applicable to the storage of pressurized fuel fluids.