Disclosed is an apparatus for cleaning a vulcanization die, including: a vacuum processing chamber; an electrode arranged in the vacuum processing chamber; a high frequency power supply connected to the electrode and a vulcanization die placed in the vacuum processing chamber; and a gas introducing pipe connected to the vacuum processing chamber, for introducing a reactive gas into the vacuum processing chamber; wherein a voltage is applied between the electrode and the die to generate a plasma of the reactive gas having been introduced into the vacuum processing chamber, and the plasma is allowed to react with an elastomer residue stuck on the surface of the die, thereby removing the elastomer residue by ashing. The apparatus is characterized by further including a microwave cavity resonator for generating a plasma, arranged in the gas introducing pipe; wherein the reactive gas is excited through the plasma generated by the microwave cavity resonator, and is then introduced into the vacuum processing chamber. According to the apparatus and method thereof, an elastomer residue stuck on the surface of a vulcanization die can be efficiently, certainly removed by ashing for a short period of time, with the reduced supply and discharge amounts of a reactive gas used.