PURPOSE: To prevent the damage of an underground tank caused by a point contact between the tank and its stand as in the conventional case by providing an underground tank stand which has a part for supporting the lower part of the underground tank with a high degree of accuracy, can respond to the deformation of the underground tank and holds the lower part of the underground tank and the supporting part of the stand always in facial contact with each other.

CONSTITUTION: An iron-made, strip-like supporting plate 1 is formed into an arcuate shape to hold the lower part of an underground tank 2 in the circumferential direction and is provided with a downwardly directed iron-made, plate-like supporting leg 3 at each end. The lower end of each supporting leg 3 is fastened to underground floor surface 4 with a bolt 5. The stands having the supporting plate 1 and the supporting legs 3 integrally formed are provided at several places in the longitudinal direction of the underground tank 2.