PURPOSE: To eliminate a shock due to switching of a moving direction of a head and enable to speed up a printing by a method wherein the ink head injecting ink drop is scanned while being rotated into a vertical direction with respect to a transferring direction of a recording paper.

CONSTITUTION: An ink head 1, injecting microscopic ink droplets 2, 2 in response to an electric signal, is scanned while being rotated into a vertical direction with respect to a transferring direction (shown by an arrow in the diagram) of a recording paper 6 opposingly arranged thereto. The rotation of the head 1 is effected by a motor 7. The recording paper 6 is transferred concentrically in a shape of a circular arc with respect to the rotary scanning of the ink head 1. A centrifugal force is acting in the rotating ink head 1 from a rotational center to an injecting nozzle 5, therefore, an equilibrium between the centrifugal force of the ink near the injecting nozzle 5 and a surface tension of the same may be kept by setting the revolving speed of the motor 7 at a desired speed.