In order to incorporate voice communication by analog terminals into an ATM network, it is important to cancel the echo associated with increased transmission delay caused by cell assembly and disassembly (CLAD) and cell delay variation (CDV) smoothing. Echo cancelers are used for suppression of echo. In cell-based echo cancelers in an ATM network, it is necessary to take into account the effects of CDV and cell loss on the echo canceling process. This paper first discusses the necessity of cell-based echo cancelers and describes their configuration and processing method. Next, it demonstrates that the processing algorithm of the cell-based echo canceler is not affected by CDV. The effect of cell loss on the quality of the echo canceler is verified by simulation. It is shown that the effect of cell loss can be divided into reconvergence from the initial value, associated with the time shift of the far-end signal and the near-end signal, and temporary quality deterioration caused by mismatch of the echo and the echo replica. Further, by studying the effect of cell loss on the processing algorithm of the echo canceler, the divergence condition of the echo canceler is derived from the condition of the echo path delay and the multiplicity of cell loss.