A method and apparatus of estimating a residual energy of a battery for an electric vehicle. A battery characteristic is corrected on the basis of a temperature correction factor and a deterioration correction factor which are obtained on the basis of the condition of the battery. The deterioration correction factor includes an internal resistance deterioration correction factor indicative of a deterioration ratio of a battery internal resistance and a energy deterioration correction factor indicative of a deterioration ratio of a battery energy. The residual capacity is calculated on the basis of the corrected battery characteristic, a discharge current and a terminal voltage of the battery. Therefore, a residual energy meter accurately displays a residual energy of the battery.