To easily remove a mold, whereon metallic fuel is solidified, without grinding metallic fuel solidified on the mold, or without destroying the mold whereon metallic fuel is solidified.

The mold holder for manufacturing metallic fuel mold body has an opening, where the mold used for manufacturing the metallic fuel mold body by ejection molding is inserted. The diameter of the opening is made so that the mold whereon the metallic fuel is solidified can pass therethrough. In the opening, a spacer formed vertically splittable and having a diameter to insert the mold whereon metallic fuel is not solidified, is installed, and a multiple spacers are installed in multiple steps in the device manufacturing the metallic fuel mold body.