A filament winding device includes: a helical winder which winds a fiber bundle around a liner; a bobbin supporting shaft which rotatably supports a bobbin for providing the fiber bundle to the helical winder and a bobbin different from the bobbin in a state in which winding-initiation ends of the fiber bundle wound around the bobbin and winding-termination ends of the fiber bundle wound around the bobbin connect to each other; and a fiber bundle storage unit. The fiber bundle storage unit has a stopper which can switch the fiber bundle storage unit between a storage state in which the fiber bundle is stored in the fiber bundle storage unit and a storage-released state in which the fiber bundle has been released from storage in the fiber bundle storage unit and the fiber bundle is supplied from the fiber bundle storage unit to the helical winding unit.