To provide a storable duration-improving agent giving a high preservability to various foods without damaging a flavor intrinsic to foods.

The storable duration-improving agent is obtained by formulating ethanol, one or more organic acids, one or more organic acid salts, amino acid and water in a specific proportion. The storable duration-improving agent is used by being mixed in, soaked in or sprayed to various foods including cut vegetable, hamburger, ham, sausage, bacon, omelet, boiled rice, marine paste products such as boiled fish paste, fried fish paste and the like, noodles such as Japanese noodles, Chinese noodles and the like, confectioneries, pickles, and condiments such as fermented soybean paste, soy sauce and the like.