To process the galley proof working of a corrugated cardboard easily in a short time.

The galley proof-printing operation machine for the corrugated cardboard includes pressing/adhering an impression cylinder around which galley paper of a matter to be printed is wound and a plate cylinder in which a printing die is mounted to a drum, and arranging an inking unit to the plate cylinder, wherein two or more inking rolls rotatably prepared at front edges of two or more radial lines prolonged from a rotation center, the desired roll of two or more inking rolls is pressed/adhered and arranged to the plate cylinder to compose the inking unit, the change of the inking roll for pressing/adhering the plate cylinder of this inking unit is made to be performed by the pivoting on a rotation center, the inking roll consists of an ink tank storing ink and a foaming layer prepared so as to cover the circumference of this tank, and the ink flowing out of an effluence hole of the ink tank is impregnated into the foaming layer and is made to be supplied to the printing die of the plate cylinder.