An FFT unit (170) separates a received symbol by Fourier conversion into a plurality of subcarriers, and a phase difference detection unit (193) detects a phase difference between 4 pilot carriers and data carriers adjacent to the pilot carriers (adjacent carriers) The decision unit (194) decides whether the phase differences between the pilot carriers and the adjacent carriers detected by the phase difference detection unit (193) fulfill a phase difference condition. Then, the decision unit (194) decides that the received symbol is an HTSIG if the number of phase differences that fulfill the phase difference condition is greater than or equal to a predetermined number, and decides that the received symbol is either a SIG or a DATA if the number of phase differences that fulfill the phase difference condition is less than the predetermined number.