To optimize an echo canceler so as to reduce as much as possible the required numbers of multipliers and adders in an adaptive filter which is a constituent component of the canceler.

The echo canceler having, a false echo generator circuit, composed of an adaptive filter passing signals transmitted from a transmit side talking terminal to generate false echoes, and a subtractor for subtracting the false echoes from received signals by a receiving side talking terminal, comprises a control circuit 150. The echo generator circuit has equivalent transmission characteristics to transmission paths of signals along which echoes turn around. The control circuit 150 controls includes in an initial state, all multipliers and adders in the adaptive filter are enabled, and in a process of correcting tap factors given to the multipliers, those multipliers and adders which not required for eliminating echoes are set to nonaction state after another from the former stage to the latter stage.