Glass molding die and renewing method thereof

A renewing method for a glass molding die, comprising:

• providing a used glass molding die comprising a substrate, a first noble metal layer overlying the substrate, a second noble metal layer overlying the first noble metal layer, a carbon-containing third noble metal layer directly on the second noble metal layer, and a diamond-like carbon (DLC) passivation film directly on the third noble metal layer;
• removing the passivation film and partially removing the third noble metal layer using oxygen plasma;
• grinding and polishing the molding die to completely remove the third noble metal layer;
• cleaning the polished molding die;
• forming a fourth noble metal layer directly on the second noble metal layer;
• and
• forming a second passivation film directly on the fourth noble metal layer, wherein the second passivation film comprises the same material as the passivation film directly on the third noble metal layer.