An ink-jet printer performs the ordinary jetting operation in which the printing is performed on a printing area of the recording paper while transporting the recording paper frontwardly by transport rollers and the marking jetting operation in which a marking is formed at an edge portion of the recording paper. A control unit of the ink-jet printer allows nozzles to jet liquid droplets therefrom in the marking jetting operation, the liquid droplets having larger volumes as compared with those jetted in the ordinary jetting operation. Therefore, in the marking jetting operation, a larger amount of the ink liquid droplets can be permeated in the thickness direction of the recording paper as compared with the ordinary jetting operation. Accordingly, the marking, which can be easily confirmed from the side of the printing medium, is formed.