To enhance drying efficiency without causing a large temperature change in a blanket.

At one place at the outer peripheral face of the blanket 2 on the outer periphery of a blanket roll 1, a drying processing area X is set which extends linearly in the roll axis direction of the blanket roll 1. An air injection nozzle 3 is provided for blowing air 4 toward the drying processing area X, and an exhaust device 6 is connected to a suction cover 5 covering the drying processing area X and the air injection nozzle 3. The air 4 is blown to the drying processing area X of the blanket 2 by the air injection nozzle 3. By the blowing air 4, the blanket 2 is deformed locally in a crushed manner, and a solvent 18 of a printing ink absorbed in the blanket 2 is squeezed out. The squeezed solvent 18 is blown away at once by a flow of the air 4, and sucked and recovered in the exhaust device 6 to be removed from the blanket 2.