PROBLEM TO BE SOLVED: To keep freshness of vegetables and fruits stored in a corrugated cardboard box.SOLUTION: As a corrugated cardboard box, a hermetically-sealed corrugated cardboard box is used which can contain an outer package, an inner package or both, which has the inner and outer exchange rate in 1-methyl cyclopropene after a lapse of one hour as not less than 11% and not more than 42%, and which has the inner and outer exchange rate in carbon dioxide after a lapse of one hour as not less than 15% and not more than 35%. The hermetically-sealed corrugated cardboard box is made to contain, together with vegetables and fruits, a drug which is capable of discharging 1-methyl cyclopropene.SELECTED DRAWING: None
