PURPOSE: To precisely lay thin stuffs one upon another at a high speed by a method wherein folding sticks are positioned on the thin stuffs and air is blown from below to wind up the thin stuffs around the folding sticks.

CONSTITUTION: A folding device consists of a space where air flows, support plates 22 on which thin stuffs M are supported by a number of support pieces arranged at intervals, folding sticks 45 which are moved to the specified upper position close to the thin stuffs M, and compressed air pipes 43 and 44 which are located below the thin stuffs M on the front side divided by the folding sticks 45 and blow compressed air to wind up the thin stuff M on the front side around the folding sticks 45 and lay them one upon another.