To provide a means capable of reliably suppressing any curl generated in a recording paper when passing through a fixing instrument by automatically adjusting the degree of corrugation to be given to the recording paper by a corrugation rib according to the flexibility of the recording paper itself.

A delivery roller device 1 comprises a delivery roller 16 in which a plurality of driving rollers 19 which are provided on a terminating end 3E of a conveying passage 3 with a recording paper P being conveyed thereon, and a plurality of driving rollers 19 are fixed to driving shafts 18 rotated with both ends thereof being supported by a device body 15 and rotated at a predetermined spacing, and corrugation ribs 17 in which tips are protruded to enter between the driving rollers 19 at the opposing position of the delivery roller 16 at the device body 15. The protrusion height of the corrugation ribs 17 from the device body 15 is changeable.