In a case where multiple kinds of frames having different lengths (Ngi_s and Ngi_l) of guard intervals inserted before the head of the effective data, the length of the guard intervals are adjusted in such a manner that at least the position of a part of the effective data is are apart from frame timing by the same amount. Thereby, on the receiving end, it is always possible to perform reception processing such as FFT processing in an appropriate time division at a fixed timing, without causing sample deviation of the effective data.