Autosampler with control unit for performing a cleaning operation

An autosampler comprising:

• a needle whose tip is formed to be tapered;
• a measuring-pump for discharging and drawing in by suction a liquid through said needle;
• a movement mechanism for moving said needle in a horizontal direction and a vertical direction;
• an injection port having a needle-sealing surface and connected to an analysis flow path via a valve;
• and
• a control unit for controlling said measuring-pump and said movement mechanism;
• wherein after a sample solution that is held in a sample vessel is drawn in by suction through said needle, the tip of said needle is pressed against said needle-sealing surface and said sample solution is discharged so that said sample solution is introduced into said analysis flow path through said injection port;
• and
• said control unit performs a cleaning operation for cleaning said needle-sealing surface by causing said measuring-pump to draw in from a cleaning liquid vessel by suction, an amount of a cleaning liquid to be held within said injection port, then causing said needle to be moved to a position where the tip of said needle does not contact said needle-sealing surface, then causing said measuring-pump to discharge said cleaning liquid, then raising said needle to a position where the tip of said needle is not in contact with the surface of the cleaning liquid that is held within said injection port, and then causing said measuring-pump to draw air in by suction and then discharge the air.