PURPOSE: To improve the quality of printing by providing a uniform ink film thickness on the surface of a printing cylinder, by using an inking roller of a particular circumferential length.

CONSTITUTION: As an inking roller 23 for applying ink to the surface of a printing cylinder 22, a roller whose circumferential length is almost equal to a noneffective surface 22b (a surface which is proided with notches for biting both ends of a printing cylinder to be mounted) of a printing cylinder 22 is used (a symbol 22a denotes an effective surface of a printing cylinder and a symbol 21 a swinging roller). When the inking roller 23 faces with starting end of the noneffective surface 22b of the printing cylinder 22, the roller 23 is provided with formation of an ink film E transferred from the swinging roller 21, and then, when the roller 23 faces with the center of the noneffective surface 22b, the ink film E has spread to an entire circumference, and then, with rotations of the rollers, a thicker ink film G is formed on entry side of the roller 23 to the printing cylinder 22, at this time, as front end of the ink film G coincides with rear end of the noneffective surface 22b, ink can be applied uniformly onto the effective surface 22a of the printing cylinder 22 without producing any difference in level.