A process for producing a glass substrate for magnetic disk through chemical strengthening operation, in which the distribution of compressive stress is uniformed at a surface layer portion of the glass substrate to thereby, while preventing failures such as head crash and thermal asperity, realize a low flying height of magnetic head, attaining high-density information recording. In particular, the provided glass substrate for magnetic disk is suitable for application to compact magnetic disks for portable information equipment. The chemical strengthening operation includes the first step of bringing the glass substrate into contact with a first treatment solution (chemical strengthening treatment solution) containing first ions with an ionic radius larger than those of ions within the glass substrate and either the second and subsequent steps of bringing the platy glass into contact with treatment solutions containing second and subsequent bivalent ions, or the second and subsequent steps of bringing the glass substrate into contact with second and subsequent chemical strengthening treatment solutions containing second and subsequent ions exhibiting an ion exchange rate with ions within the glass substrate greater than that of the first ions to thereby decelerate the ion exchange.