This method for inhibiting protease in a biological sample containing pancreatic juice components inhibits protease enzyme activity in the biological sample by adding at least one type of protease inhibitor having a sulfonyl fluoride group to the biological sample containing pancreatic juice components. In addition, this protease inhibitor for a biological sample containing pancreatic juice components is a compound having a sulfonyl fluoride group, has protease inhibitory activity, and is added to a biological sample containing pancreatic juice components in order to inhibit protease present in the biological sample. Moreover, this kit for preserving a biological sample containing pancreatic juice components contains at least one type of protease inhibitory having a sulfonyl fluoride group, and is used to store a biological sample containing pancreatic juice components.
