The invention relates to a combination tank having a double-walled inner container for temperature-insulated accommodation of a cryogenic fluid, which inner container has an approximately circular cylindrical cross-section and is closed off with end-side caps, wherein an outer container for accommodating at least one operating material is configured around the inner container, which outer container has a jacket having an approximately rectangular cross-section and end walls supported on the inner container, which end walls either sit in the gussets that remain between inner container and jacket, or are touched or penetrated by the caps of the inner container.