To provide a cistern structure which can reduce an installation space, can be simply installed, facilitates the securement of strength, and allows the storage of liquids with a plurality of systems.

Cisterns 3 are provided in a state of being adjacent to each other; a channel 15 is joined to an inside side plate of one cistern 3; a bolt 35 is liquid-tightly passed from inside the cistern 3 through an inside side plate 3a of the other cistern 3, facing the inside side plate of one cistern, without making the channel 15 joined to the plate 3a of the other cistern 3; and the bolt 35 is coupled to the channel 15, so that the adjacent cisterns 3 can be integrated together so as to serve as a cistern complex 1.