[en] A hollow foam sphere is completely immersed in liquid heavy hydrogen fuels and heated externally. Liquid impregnated to the inside of the hollow sphere driven out by the heating step. Accordingly, it is possible to prepare a target in which liquid fuel is impregnated only to the portion of the foam wall. Further, according to the fuel charging device for the cryogenic form target of this invention, fuel gas is liquefied and the form hollow foam sphere is completely immersed in the liquefied fuel. Subsequently, the hollow foam sphere is heated by the heating device to drive out the liquids impregnated to the inside of the hollow sphere. Accordingly, it is possible to manufacture a target in which the liquefied fuel is impregnated only to the portion of the foam wall. As a result, an appropriate amount of fuel can be charged uniformly only at the portion of the foam wall. Further, this is also applicable to mass production of targets in near future. (I.S.)