To provide a paper delivery unit, a printer and a seasoning method by which paper sheets after printing can be surely seasoned one by one and by which prevention of show-through and improvement in work efficiency can be attained.

The paper delivery unit used in a paper delivery section of a printer includes: a paper conveying means 22 that, before stacking printed paper sheets 12 on a stacking base 20, holds paper sheets 12 one by one to form a gap between the paper sheets and to move these paper sheets toward the stacking base 20; and an air blowing means that ventilates the gaps between the paper sheets 12 during their conveyance by the paper conveying means 22. The paper conveying means 22 is provided with a plurality of holding mechanisms capable of holding and releasing the paper sheets 12. In addition, paper moving speed by the paper conveying means 22 is set slower than the moving speed of the paper sheets by a conveyance mechanism 14 before the delivery of the paper sheets 12.