PROBLEM TO BE SOLVED: To provide a method of sterilizing vegetables without using a sterilization drug and without deteriorating quality.SOLUTION: A vegetable package in which vegetables are enclosed in a plastic container and hermetically sealed is immersed in a heated water of 45-59°C. With the elapsed time of 4-6 minutes after the central temperature of the vegetable package reaches the same temperature as the heated water, the vegetable package is taken out from the heated water and then immersed to cool in running water. In addition to this sterilization method of vegetables, a long-keeping improver is added to the resin container, thereby making it possible to provide a long-life product.SELECTED DRAWING: None