PROBLEM TO BE SOLVED: To provide a beverage with a high concentration of thiamin, a thiamin derivative, or a salt thereof having an improved flavor, by reducing the unpleasant odor occurring with the passage of time, which is inherent to thiamin, a thiamin derivative, or a salt thereof.SOLUTION: A beverage including 0.05 W/V% or more of thiamin, a thiamin derivative, or a salt thereof, further includes one or more than two selected from the group consisting of &gamma；-undecalactone, benzyl acetate, and ethyl isovalerate, so as to provide a method for improving the flavor.
