PROBLEM TO BE SOLVED: To provide a preservation liquid for separation membranes having high safety and excellent handling easiness, free from the lowering of performance by the deterioration of the separation membrane and capable of suppressing the proliferation of bacteria and molds for a long period, a separation membrane module having excellent long-term preservability, resistant to the discoloration and foaming caused by the preservation liquid and having little restriction on the packaging material and preservation environment, and a method for the preservation of separation membranes. SOLUTION: The preservation liquid for separation membranes is composed of an aqueous solution containing benzoic acid and/or a benzoic acid salt in an amount of preferably 0.05-0.5 mass%. The preservation liquid for separation membranes preferably has a pH of≤4.5 at 25°C, a separation membrane module is filled with the preservation liquid for separation membranes, and a method for preservation of a separation membrane includes immersion of the separation membrane in the preservation liquid for separation membranes. COPYRIGHT: (C)2007,JPO&INPIT
