An equalizer can connect with N receiving antennas that receive single carrier transmission signals transmitted from M transmitting antenna(s) in the same frequency band at the same time, and receives as input L signals sampled in a sampling period T from each of the N receiving antennas, the equalizer comprising, a first selection part that selects K signal(s) from the L signals for each of the N receiving antennas as signals to be multiplied by a first tap coefficient(s), and a second selection part selects L-K signal(s) to be multiplied by a second tap coefficient(s), from the L signals obtained by multiplying signals in the same sampling period for each of the N receiving antennas by the tap coefficient(s) and performing addition thereof.