A storage tank 10A has a heat insulating material layer 14 formed on the outer side of a partition wall 12 that has a container shape. The inside of the storage tank 10A is divided into two storage spaces V1, V2 The first storage space V1 stores liquefied hydrogen LH2 and the second storage space V2 storing slush hydrogen SH2. A plurality of fins 18 are disposed on the partition plate 16 so as to promote heat transfer between the liquefied hydrogen LH2 and the slush hydrogen SH2 and to reduce the amount of evaporation gas from the liquefied hydrogen LH2. An escape pipe 20 is connected to the storage space V1, and the fuel supply pipes 24a, 24b are connected to the storage spaces V1, V2, respectively. The fuel supply pipes 24a, 24b are connected to a combustor 26 via the main fuel pipe 24.
