PURPOSE: To improve adhesive force between a base and a regenerated hard carbon film by removing a hard carbon film using the oxygen plasma ashing method, subsequently treating the molding surface with hydrogen fluoride and then forming a new hard carbon film in regeneration of a glass-forming mold with a hard carbon film formed on a silicon-containing base.

CONSTITUTION: Press forming of a glass lens, etc., is carried out using a glass- forming mold with a hard carbon film formed on a silicon-containing base (e.g., silicon carbide base). In regeneration of the glass-forming mold, a hard carbon film is initially removed using the oxygen plasma ashing method and the molding surface of the forming mold is then treated with an aqueous solution of hydrogen fluoride or a salt thereof to remove silicon oxide with a weak adhesive force to the hard carbon film and expose silicon carbide with a strong adhesive force thereto. A new hard carbon film is subsequently formed on the base using the sputtering process, etc., and the resultant regenerated glass- forming mold can be repeatedly used many times without occurrence of release of the hard carbon film.