Polishing apparatus

A polishing apparatus comprising:

• a substrate holder configured to hold a substrate and rotate the substrate, the substrate holder including a plurality of rollers which are rotatable about their own axes, the plurality of rollers having substrate-holding surfaces capable of contacting a periphery of the substrate;
• a polishing head configured to bring a polishing tape, having abrasive particles on one surface, into contact with a back surface of the substrate to polish the back surface, the polishing head being disposed below the substrate-holding surfaces, the polishing head including a plurality of polishing blades configured to press the polishing tape against the back surface of the substrate, and a plurality of pressing mechanisms a pressing mechanism configured to push the plurality of polishing blades upward, respectively, the plurality of pressing mechanisms being configured to operate independently of each other, the plurality of polishing blades including a first polishing blade and second polishing blades, a distance from an axis of the substrate holder to the second polishing blades being larger than a distance from the axis of the substrate holder to the first polishing blade, the second polishing blades being located at the same distance from the axis of the substrate holder, the second polishing blades extending in different directions;
• a tape advancing device configured to advance the polishing tape in its longitudinal direction;
• and
• a translational rotating mechanism configured to cause the polishing head to make a translational rotating motion.