Abstract: For preserving fresh foods at low cost, using a packing material safe for global environment, while the freshness, color, taste and texture of the fresh foods are retained, a method of the present invention arranges broccoli in a corrugated carton box in which a freshness-keeping bag is spread, and sprays water on the broccoli at farms. The corrugated carton boxes are loaded on a pallet at a selection platform to be then placed in a preliminary vacuum chamber to preliminarily cool the broccoli in vacuum. The corrugated carton boxes on the pallet are placed in a cold insulation chamber and the opening of the freshness-keeping bag is closed. Cooling air blown from a cooler in an enforced manner is circulated through an air permeable hole of the corrugated carton box in the cold insulation chamber, to cool the broccoli in the corrugated carton box.