A demodulation device comprises at least a diversity combiner, an elimination parameter storage, an elimination parameter investigator, a noise eliminator, and a noise collection means. The elimination parameter storage stores elimination parameters used for eliminating a noise, as elimination parameters for each of antennas, the noise collection means receives a noise and outputs the received noise as a collected noise signal, and the diversity combiner outputs a combined signal along with combining parameters, each representing a parameter related to the combining for each of the antennas. The noise eliminator eliminates the noise by using the elimination parameters for all the antennas as well as the combining parameters for all the antennas.