To provide a printing device equipped with an image projecting means which can manufacture a high precision printing plate of a simple configuration, in the printing device which manufactures a printing plate aboard.

In this printing device, a plurality of projecting means 8 are arranged on an array head 7 at the same interval in a straight line parallel with a rotary shaft of a plate drum 250 as an image projecting means which manufactures the printing plate aboard the printing device; and the array head 7 is mounted on a movable member 6. In addition, guide means 9 and 10 which guide the array head 7 retaining the projecting means 8 by the interval between at least the adjacent projecting means 8, together with the movable member 6, in the axial direction (a) of the plate drum 250 during the projection and a drive means 11 for moving the movable member 6 in the axial direction (a), are provided.