| abstract |
PROBLEM TO BE SOLVED: To provide a glass substrate for an information recording medium in which high cleanliness and high smoothness can be easily obtained by acid treatment. In order to keep <0.3 nm, it is necessary that the etching rate of the 0.1% by weight aqueous hydrofluoric acid solution at a temperature of 50 ° C. of the substrate glass is 45 nm / min or less as an index of acid resistance. [Selection figure] None |