To suppress nonlinear echoes with a small operation amount by canceling the nonlinear echoes by a filter which forms an adaptive beam former.

An adaptive filter 4 estimates an echo path sneaking around from a speaker 3 to a microphone 1 and calculates its own filter coefficient. An adaptive filter 5 estimates an echo path sneaking around from the speaker 3 to a microphone 2 and calculates its own filter coefficient. A filter 7 performs the convolutional operation of the filter coefficient of the adaptive filter 5 and transmission signals inputted from the microphone 1, and a filter 8 performs the convolutional operation of the filter coefficient of the adaptive filter 4 and transmission signals input from the microphone 2. A subtraction part 9 subtracts the convolutional operation results of the filter 7 and the convolutional operation results of the filter 8 to suppress the nonlinear echoes.