Nozzle cleaning method and automated analyzer

A nozzle cleaning method consisting of:

• a first cleaning step of cleaning an inner wall surface of a dispensing nozzle located at a first position in a cleaning tank by discharging a preloaded solution from the inside of the dispensing nozzle, and concurrently cleaning an outer wall surface of the dispensing nozzle located at the first position by discharging a cleaning solution from a pair of first discharge ports to the outer wall surface of the dispensing nozzle;
• a second cleaning step of cleaning the inner wall surface of the dispensing nozzle located at a second position in the cleaning tank by aspirating the cleaning solution stored in a storage tank of the cleaning tank into the dispensing nozzle;
• and
• a third cleaning step of cleaning the inner wall surface of the dispensing nozzle located at a third position in the cleaning tank by discharging the cleaning solution aspirated into the dispensing nozzle, and concurrently cleaning the outer wall surface of the dispensing nozzle located at the third position by discharging the cleaning solution from a pair of second discharge ports to the outer wall surface of the dispensing nozzle.