MANUFACTURING METHOD OF GLASS SUBSTRATE FOR MAGNETIC DISK

There is disclosed a manufacturing method of a glass substrate (2) for a magnetic disk (1), comprising: forming a sheet glass material by press forming a lump of molten glass while sandwiching the lump from opposing sides using surfaces of a pair of dies (121, 122) set at approximately the same temperature, such that the surfaces of the pair of dies (121, 122) are brought into close contact at approximately identical timing; and polishing a principal surface of the sheet glass material by pressing a polishing pad (10) against the principal surface of the sheet glass material while supplying a polishing solution including a polishing material between the sheet glass material and the polishing pad (10), and relatively moving the sheet glass material and the polishing pad (10).