Flow path washing method of auto sampler and flow path washing apparatus of auto sampler

A flow path washing apparatus of an auto sampler, comprising:

• a first flow path including a nozzle for aspirating a sample and a sample loop for holding the sample aspirated from the nozzle;
• a second flow path including a washing tub for washing at least an outer wall of the nozzle;
• a cleaning fluid supply mechanism for supplying cleaning fluid to the first flow path and the washing tub through the second flow path, respectively;
• a flow path switching mechanism for switching a supply destination, of the cleaning fluid supplied by the cleaning fluid supply mechanism to the first flow path and the second flow path;
• and
• a control unit configured to change a flow velocity of the cleaning fluid supplied between measurement of a first substance and measurement of a second substance based on, among washing information showing washing patterns corresponding to different measurements of substances, first washing information showing a washing pattern corresponding to the first substance, second washing information showing a washing pattern corresponding to the second substance to be measured subsequent to the first substance, and third washing information showing a washing pattern corresponding to a third substance measured before the first substance.