A polishing apparatus includes a loading section (14) for placing therein a cassette (12) in which a plurality of polishing objects are housed; a first polishing line (20) and a second polishing line (30) for polishing a polishing object; a cleaning line (40) having cleaning machines (42a, 42b, 42c, 42d) for cleaning the polishing object after polishing and a transport unit (44) for transporting the polishing object; a transport mechanism (50) for transporting the polishing object between the loading section (14), the polishing lines (20, 30) and the cleaning line (40); and a control section for controlling the polishing lines (20, 30), the cleaning line (40) and the transport mechanism (50). The control section determines a polishing start time in each of the first and second polishing lines (20, 30) based on a predicted polishing time in each of the first and second polishing lines (20, 30), a predicted transport time in the transport mechanism (50), a predicted cleaning time in the cleaning line (40) and a predicted cleaning start time to start cleaning by driving the transport unit (44) of the cleaning line (40).