Disclosed is a CFO estimation method, which generates a first function defined by a received signal of two sequential OFDM symbols for a specific subcarrier, generates a second function defined on the basis of signs and magnitudes of a real number part and an imaginary number part of the first function, repeats the steps of generating the first function and the second function for all of a subcarrier set, and determines, as a residual CFO, a phase of a third function obtained by adding up the results of the repetition.