A data processing part comprises a time-series data production part for producing time-series data as to each capillary column from a scan waveform obtained by an optical measuring part, further comprises a correction data storage part for storing correction data indicating the relation between the number of data points of saturated parts and light intensity data obtained on the assumption that a peak is unsaturated as to a saturated scan waveform peak and a saturated data correction part obtaining light intensity data as to the saturated peak included in the scan waveform on the basis of the correction data stored in the correction data storage part, and employs the light intensity data obtained by the saturated data correction part as the time-series data.