Abstract: A method of manufacturing a magnetic disk glass substrate has a cleaning step of cleaning the glass substrate. In the cleaning step, the cleaning is performed under an acidic condition using a cleaning liquid containing oxalate ions and bivalent iron ions. In parallel with the cleaning step or before or after the cleaning step, trivalent iron ions generated by oxidation of the bivalent iron ions contained in the cleaning liquid are reduced by ultraviolet irradiation.

Abstract: Provided are: a method for manufacturing a glass substrate for a magnetic disk by using an alternative abrasive having the same polishing performance as cerium oxide, which has conventionally been used as an abrasive for polishing principal faces of glass substrates for magnetic disks; and a method for manufacturing a magnetic disk. At the time of polishing a principal face of a magnetic disk glass substrate by using a slurry, the disclosure employs a slurry containing: an abrasive made of granular zirconia; a first additive including a phosphate and/or a sulfonate; and a second additive including a re-aggregation inhibitor.