A print head which includes at least two discharge nozzle lines arranged on at least two lines, out of a base line corresponding to a radial direction of the rotating print object and at least one offset lines parallel to the base line, discharges ink drops of the same color from discharge nozzles of the discharge nozzle lines, moves the print head so as to minutely move the discharge nozzle lines on the base line or the offset lines, and discharges ink drops of the same color from the discharge nozzles passing through second paths moved minutely from the first paths over the rotating print object. In this way, the ink drops are discharged on the area where print defects are caused because the area is not on the paths of the discharge nozzles before the discharge nozzles are minutely moved.