Disclosed is a method for estimating the maximum power of a battery, which can inexpensively perform an estimation of the maximum power of a battery in a relatively simple manner of using the internal resistance of the battery, which has a correlation with and a largest effect on the maximum power of the battery. The method includes the steps of: measuring an internal resistance and a temperature of the battery and estimating a state of charge, if an estimation of the maximum power of the battery is requested; and reading a value of the maximum power of the battery, which corresponds to the measured temperature, the estimated state of charge, and the measured internal resistance, from a table in which the internal resistances and the maximum powers of the battery are mapped according to the temperatures and states of charge.