Abstract: In a printing paper seasoning apparatus, sheets of paper are placed in a stack in a paper accommodating section. A direction to which convex sides of curled sheets face is taken as a curl direction. An air flow is controlled in such a manner that during an initial period of an air blowing, the air flow supplied to one of the upper and lower portions of the paper accommodating section on a side opposite from the curl direction is greater than the air flow supplied to the other of the upper and lower portions on a side of the curl direction, and during a latter period of the air blowing, the air flow supplied to the one of the upper and lower portions on the side opposite from the curl direction is reduced and the air flow supplied to the other on the side of the curl direction is increased.