A reaction cassette for a glycated hemoglobin meter and a measuring method thereof are provided. The reaction cassette for the glycated hemoglobin meter includes: a first zone receiving a first reagent and a blood sample; a second zone receiving a second reagent; a reaction zone in which the blood sample reacts with the first reagent, or through which the second reagent passes to react with a first blood sample mixture obtained by reacting the blood sample with the first reagent; and a measurement zone measuring an amount of total hemoglobin in the first blood sample mixture, or measuring an amount of glycated hemoglobin in a second blood sample mixture obtained by reacting the first blood sample mixture with the second reagent, wherein the blood sample, the first reagent, and the second reagent move between the reaction zone and the measurement zone according to a rotation angle of the reaction cassette when the reaction cassette is rotated. Therefore, since the reaction cassette rotates automatically, it is possible to measure the amount of glycated hemoglobin in a blood sample through simple manipulation and reduce a manufacturing time. Furthermore, since reagents are supplied to the reaction cassette from a separate reagent pack, it is possible to resolve storage and distribution problems of the reaction cassette, which occur when reagents are stored in the reaction cassette.