the invention provides an inkjet printer that gives an excellent print quality by accelerating the traveling speed of an ink droplet ejected from a nozzle of the inkjet head . the inkjet printer includes the inkjet head having a surface forming a nozzle and adapted to eject droplets from the nozzle , an ultrasound radiator mounted on both sides of the surface and adapted to radiate ultrasound in the direction of the ink droplets that have been ejected and imparting a pressure , in flight , to the ink droplets that have been ejected , and a recording medium conveying unit for moving a recording medium relative to the inkjet head .