A reduced size vacuum die-casting machine wherein an amount of powder release agent which is fed to a mold cavity each time is stable and loss of velocity of the air flow for sucking out the powder release agent is difficult, the apparatus provided with a powder control valve which has a powder release agent passage through which a powder release agent passes and which moves back and forth inside of a sleeve to switch between a state communicating a discharge hole with a molten metal holding chamber and a state communicating a discharge hole with a powder release agent passage, the powder release agent passage of the powder control valve formed inside of the powder control valve, the inlet and outlet of the powder release agent passage being formed at the outer surface of the powder control valve.