<p>An adaptive equalizer capable of suppressing an increase in circuit scale and an increase in operation clock frequency. An adaptive equalizer (100) performs an adaptive equalization process on a time-region signal in a frequency region. A signal converter (200) has: a first wide-bit memory (201) capable of reading/writing a plurality of sample signals; a first register group (202) comprising a plurality of registers capable of accessing the first wide-bit memory (201); a butterfly computation unit group (204) comprising a plurality of butterfly computation units; and a first connection switching unit (203) for switching the state of connection between the plurality of registers and the plurality of butterfly computation units.</p>