Abstract: A method of manufacturing a glass blank for a substrate for an information recording medium, the method including steps of: cutting out a gob of a glass material from a molten glass material by cutting the molten glass material discharged from a glass material outlet at a predetermined timing; causing the gob of the glass material to fall downwardly; pinching and pressing the gob of the glass material by a press unit having a pair of molds, the molds' surfaces facing to each other being press surfaces which are planes without an unevenness, so as to contact the falling gob of the glass material only to the press surfaces; and forming a circular flat plate-shaped glass blank having a target flatness as a glass substrate for a magnetic disk such that a ratio between a diameter and a thickness of the glass blank is within a range of from 50:1 to 150:1, from the gob of the glass material.

Abstract: The present invention provides a shaft high temperature continuous graphitizing furnace comprising a furnace body comprising a feeding inlet and a discharging outlet, an electrode pair, a cooling system and a discharging device; the furnace body is designed to be a shaft cylindrical structure; the electrode pair is provided within the furnace body and comprise an upper electrode and a lower electrode, the upper electrode is located below the feeding inlet, and an umbrella or cone table shape electric field having a lower cross section area greater than its upper cross section area arises between the upper electrode and eh lower electrode; and the cooling system is located between the lower electrode and the discharging outlet.