To prevent sound signal delay resulted from an echo processing from being increased at an echo canceler in a packet-type transmission line.

The remaining echo component of the output of a substructure for echo cancel 6 is speed-converted in a buffer 4. A reception packet is speed- converted in a buffer 1. The outputs of both buffers 1 and 4 are referred to and an echo path estimation unit 2 generates a filter coefficient for estimating an echo path. An adaptive FIR filter 3 convolution-operates the filter coefficient and the output of the buffer 1 and generates a pseudo echo component. A buffer 5 makes the pseudo echo component into a packet and the subtracter 6 executes subtraction on it with a transmission packet and cancels echo. Since only a subtraction processing is executed in a transmission packet line, packet delay does not exist.