An object of the present invention, in the refining process of the molten glass, to provide a production method and production apparatus of the glass substrate of the glass substrate can be suppressed that the foreign substances mixed in molten glass.
Method of producing a glass substrate is provided with a melting step, a fining step, a molding step. In the refining process, the molten glass G flows to the inside, vapor space (41c) of the clarifier tube (41) of the platinum or the platinum alloy is formed. Vapor space (41c), in the interior of the tube clarifier 41, the space above the molten glass G in the liquid level LS. Fining tube 41, it has a vent pipe clarifier tube (41a) that protrudes outward from the outer surface of (41) and, receiving portion (41d) which is installed above the liquid level LS of the molten glass G. Vent pipe (41a) is thereby communicated with the outer space of the vapor space (41c) and the fining tube 41. Receiving portion (41d), in the present case therefore the vent pipe (41a) the length of the vent pipe (41a), covers a part of the cross section of the vent pipe (41a).