PURPOSE: To surely pile sheets, by arranging an air nozzle in the end part of a conveyer toward a lower surface position of a piling device.

CONSTITUTION: A belt conveyer 4, continuously conveying a sheet 1, successively fed out and overlapped, and a conveyer 5, collectively accumulating a carried-in sheet 2 and conveying an accumulated sheet 3, are provided, then the conveyer 5 is continuously moved in the direction of an arrow head at a suitably higher speed than of the conveyer 4. Compressed air is blown from an air nozzle 6 to an upper surface of the carried-in sheet and a lower surface of the accumulated sheet in the conveyer 5, thus friction in the lower surface of the sheet is decreased further static electricity of the sheet suface is removed. In this way, the sheet can be correctly piled to perform simplification between processes.