To provide a rolled blanket drying device capable of efficiently drying a solvent of printing ink soaked into a blanket disposed on an outer peripheral portion of a blanket roll in printing processing by an offset printing device, and reducing a size of a device configuration in comparison with the case of drying the blanket only by circulation of the air.

The rolled blanket drying device I includes an ultrasonic irradiation means 3 for irradiating an ultrasonic wave 4 while focusing the ultrasonic wave to a linear region X extending in the roll axial direction on the outer peripheral face of the blanket 2 of the blanket roll 1, an air injection nozzle 5 for injecting air 6 in a state of increasing a flow velocity to the same region X, and a drying cover 7 covering an upper part and the circumference of the ultrasonic irradiation means 3 and the air injection nozzle 5. By irradiating the ultrasonic wave 4 focused by the ultrasonic irradiation means 3 to the region X of the outer peripheral face of the blanket 2, the blanket 2 is vibrated, thus an evaporation area of a solvent of the printing ink by a surface wave is enlarged, the distillation to a surface side of the solvent by the inside compression wave is promoted, and vaporization by applying the energy of the ultrasonic wave to the solvent itself is promoted, and furthermore, by constantly reducing solvent vapor pressure near the surface of the blanket 2 by the air 6 injected by the air injection nozzle 5, the evaporation of the solvent can be promoted.