US Patent 7837536 Polishing apparatus, polishing brush and manufacturing method of disk-shaped substrate

The polishing apparatus that polishes an inner circumferential surface of a disk-shaped substrate including a portion having a hole at the center thereof, the polishing apparatus is provided with: a rotating table that holds piled workpieces in which a plurality of disk-shaped substrates are piled, a polishing brush that is inserted into a portion having the hole of the disk-shaped substrates of the piled workpieces and is rotated, a cover member that covers the piled workpieces, and a polishing-liquid flowing-in unit that flows polishing liquid into the portion having the hole of the disk-shaped substrates of the piled workpieces covered by the cover member.