Patent ID: 8715777

Claim:
A method for producing a glass substrate for a magnetic disk comprising: forming a cut line in a circular shape in one surface of a planar glass material so as to draw a curve extending along a substantial periphery of a region in which a glass substrate for a magnetic disk is to be formed; and allowing the cut line to extend in a thickness direction of the glass material, thereby cutting a disk-shaped glass plate; and making the glass substrate for the magnetic disk from the cut glass plate, wherein, when the cut line in the circular shape is formed in the glass material and then cutting is performed, the cutting is performed under the conditions where the radius of the circle (r [mm]) and a maximum height of a surface waviness (PV [nm]) of the glass material satisfy a predetermined relationship; wherein the predetermined relationship is PV≦5×r; wherein the surface waviness of the one surface falls within a waviness wavelength band between 0.1 mm and 5 mm; and wherein the cut line has a radius not greater than 10 mm.