PURPOSE: To increase the number of taps with simple constitution, by connecting plural stages of a signal processing circuit which feeds the information needed for correction of a signal series and an internal parameter and delivers a signal series showing a signal process and the correcting information.

CONSTITUTION: The 1st signal processing circit 1001 feeds the 1st and 2nd signal series xz and yi from the outside of an echo canceler and also the correcting information Δhi needed for correction of an internal parameter from the K-th signal processing circuit 100k. Then the 3rd signal series showning the result of signal process and the correcting information are delivered to the 2nd signal processing circuit 1002. The 2nd∼K-th signal processing circuits 1002∼100K have the same operations as the circuit 1001, and a part ej of a signal series delivered from the circuit 100K is delivered to the outside.