Abstract: A multiple storage tank system includes: storage tanks in which cryogenic fluid is stored; discharge lines connected to the storage tanks to discharge the stored cryogenic fluid or introduce cryogenic fluid; a supply line connected to the discharge lines and a supply target to supply the discharged cryogenic fluid to the supply target; a build-up line branching off the supply line to control internal pressure of a first storage tank of the storage tanks; and a gas transfer line connected to the storage tanks to transfer gas inside the storage tanks, wherein when the internal pressure of the first storage tank is controlled while the cryogenic fluid passes through the build-up line, gas inside the first storage tank is transferred to at least one other storage tank through the gas transfer line so that internal pressure of the at least one other storage tank is controlled.