PROBLEM TO BE SOLVED: To provide a new sterilization technology for producing retort food with high quality stability by lessening a heat history difference when heat-sterilizing, caused by an initial temperature difference before heat sterilizing between products in a package product group stored in a retort boiler.SOLUTION: The batch type retort sterilization method for heat sterilizing a package product obtained by filling a container with contents and sealing includes cooling the package product before heat sterilizing the package product. The cooling is performed after storing the package product in a retort boiler.COPYRIGHT: (C)2011,JPO&INPIT【課題】レトルト釜内に収容される容器詰め製品群における製品間での加熱殺菌前の初期品温差に起因する加熱殺菌時の熱履歴差を小さくして、品質安定性の高いレトルト食品を製造するための新規な殺菌技術を提供する。【解決手段】容器詰め製品を加熱殺菌する前に、該容器詰め製品を冷却する。【選択図】図1