Abstract: Provided are a double-side polishing apparatus and a double-side polishing method which can terminate double-side polishing of a workpiece so that the workpiece will have a desired shape even when double-side polishing of the workpiece is performed repeatedly. The control means determines, from a reference time point determined based on the amplitude of the change of the temperature of the carrier plate, an offset time for the next batch during which additional double-side polishing is performed; and terminates double-side polishing after a lapse of the determined offset time from the reference time point. The offset time is determined based on a predicted value of the shape index of the workpiece in the next batch, predicted from the actual value of the shape index of the workpiece having been double-side polished in one or more previous batches and from difference of the offset time between batches.