Underground storage tank consisting of an internal metal structure (1), a static external facing (2) in contact with the surrounding soil (3) and a filler (5) located between the metal structure (1) and the static facing (2), the filler (5) being stabilized by a netting (6) secured onto the metal structure (1) by joint plates (7), while the netting is embedded in the filler (5) which is thickened by charging vessels (18) combined with feed bushes (15) through which the filler (5) is poured into the cavity wall. For Liquid Gas Low Temperature Storage Tanks, the transverse channels (4) for detection and drainage of any leaks are consisting of two omega shaped sections (21, 22) whereas blown or non-blown bitumen to which polymers are added is used as a filler (5).