PURPOSE: To enable measurement with a slight waiting time after a long-term dwell, by setting the device in a stand-by state, stopping the operation of a detector and keeping a carrier fed intermittently while not in measurement.

CONSTITUTION: A carrier from a carrier storage tank 1 is fed to a sepn. column 4 by a constant volume feed means 2 and a sample is kept introduced into the column by a sample introducing device 3 in a measurement state. A stand-by state is selected by a selection means 6 while not in measurement. The operation of a detector 5 is stopped by the signal from the means 6 and setting means 7 for intermittent liquid feed is driven so that the means 2 feeds intermittently the liquid in the stand-by state.