A polishing device is provided to suppress deterioration in reproducibility of a polishing profile due to a variation or change with time of a shape of a retaining ring of a substrate holding member for each of retaining rings. The polishing device includes: a polishing head configured to press a substrate against a polishing pad and have a retainer ring surrounding the substrate pressed against the polishing pad; a measurement sensor configured to measure a surface shape of the retainer ring; and a controller configured to determine a polishing condition of the substrate based on the surface shape of the retainer ring measured by the measurement sensor.