Patent ID: 8092280

Claim:
A method for producing a glass substrate for a magnetic disk, said method comprising a step of polishing a main surface of a circular glass plate while supplying a polishing slurry containing a polishing material, wherein polishing is performed, after a polishing surface is subjected to dressing treatment, by using a polishing pad having: a first resin foam layer which forms the polishing surface, comprises a resin foam having pores with a pore diameter of more than 20 μm and up to 40 μm has a thickness of 300 to 350 μm; and a second resin foam layer which is provided between a platen for fixing the polishing pad and the first resin foam layer, comprises a resin foam having pores with a pore diameter of 10 to 20 μm and has a thickness of 75 to 200 μm, and wherein a total thickness of the first resin foam layer and the second resin foam layer is 375 to 550 μm, and a international rubber hardness degree of the polishing pad measured by the M method according to JIS K6253 is 42 to 50 IRHD.