a delay variation buffer controller allowing proper cell delay variation control reflecting an actual network operation status is disclosed . a detector detects an empty status of the data buffer when data is read out from the data buffer at intervals of a controllable time period . a counter counts the number of contiguous times the empty status was detected . a proper time period is calculated depending on a value of the counter at a time when the empty status is not detected and the value of the counter is not zero . a timing corrector corrects the controllable time period to match the proper time delay and setting the controllable time delay to a predetermined value when the empty status is not detected and the value of the counter is zero .