(EN) POLISHING METHOD OF MAGNETIC DISK SUBSTRATE

(EN) An object of the present invention is to provide a method for polishing a magnetic disk substrate which can reduce halation by adjusting a carrier peripheral speed of a carrier during polishing and a polishing composition used for polishing. The polishing method involves polishing a magnetic disk substrate 4 using a polishing composition and a polishing machine 3, and the polishing method including: a polishing composition preparation step of preparing the polishing composition; a pad surface abutting step of abutting the pad surface on substrate surface; a polishing composition supplying step of supplying the polishing composition; a rotation step of rotating surface plates and polishing pads; and a planetary motion step of planetary motion of carriers 5 on which the magnetic disk substrate 4 is mounted. The polishing composition used for polishing contains at least colloidal silica, an acid, and an oxidizing agent, and has a value of pH at 25°C of 1.3 or more and 4.0 or less, and the content of sulfuric acid in the acid constituting the polishing composition is 0% by mass or more and 1.0% by mass or less. [no suitable figure]