A polishing apparatus to simultaneously polish both surfaces of a work, and includes a pair of stools rotating in opposite directions, a pair of detecting units to detect rotation rates of the stools, a pressurizing unit to compress the work between the pair of the stools, a slurry supply unit to supply a slurry to the stools, and a control unit to reduce, when determining that a frictional force between the polishing surface and the work exceeds a threshold, at least one of a load applied by the pressurizing unit, the rotation rate of the stools, and a supply amount of the slurry.