High image quality is maintained even on front and rear ends of a printing medium where deterioration in the image quality is more likely to occur due to reduction in conveyance accuracy of the printing medium. In printing on the front and rear ends, the printing medium being not supported by both conveying means respectively placed upstream and downstream of a printing point in a printing medium conveying direction, a print swath of a printing head and the amount of conveying a printing medium are reduced. Moreover, the reducing print swath and the reducing conveyance amount are designed to be decreased in the cases of selecting a printing medium for high-quality printing as well as a monochrome print mode where image distortion caused by deviation of ink-landing positions is more noticeable due to a small number of colors of ink to be used and low coverage thereof.