There is provided a device for generating a heavy-ion beam. The device includes a laser beam generating unit configured to generate a laser beam; a target configured to generate a heavy-ion beam by the laser beam; a laser optical system configured to focus the laser beam on the front of the target; and a plasma treating unit disposed at a rear surface of the target and configured to remove impurities within the target by plasma surface treatment that is performed by radiating cationic plasma onto the rear surface of the target.