Abstract: A method of manufacturing a glass blank for a magnetic recording medium glass substrate in which, after a pair of press molds placed so as to be opposed to each other in a horizontal direction with press-molding surfaces thereof and the temperatures of the press-molding surfaces being substantially the same are brought into contact with a molten glass gob substantially at the same time, press molding is carried out to produce plate glass and the plate glass continues to be pressed with the pair of molds, and then, when the plate glass is taken out, the duration time of pressing the plate glass is controlled so that the flatness of the glass blank is 10 ?m or less, and a method of manufacturing a magnetic recording medium glass substrate, a method of manufacturing a magnetic recording medium, and an apparatus for manufacturing a glass blank for a magnetic recording medium glass substrate using the same.

Abstract: Provided are a method of manufacturing a glass blank, the method including press-molding a molten glass gob under a state in which a separation mark formed on an upper surface of the molten glass gob faces at least one of the molding surface sides of a pair of press molds arranged facing each other in a horizontal direction, when the molten glass gob falls into a space between the pair of press molds, and a method of manufacturing a magnetic recording medium substrate and a method of manufacturing a magnetic recording medium, both using the glass blank.

Abstract: Provided is a method of manufacturing a glass blank for a magnetic recording medium glass substrate, including: manufacturing a glass blank by at least press molding a falling molten glass gob with a pair of press molds both so as to face each other in a direction perpendicular to a direction in which the molten glass gob falls, in which: the molten glass gob is formed of a glass material having a glass transition temperature of 600° C. or more; and when the press molding is carried out so that the molten glass gob is completely extended by pressure and molded into a flat glass between press-molding surfaces of the pair of press molds, at least a region in contact with the flat glass in each of the press-molding surfaces of the pair of press molds forms a substantially flat surface.