An automatic analyzer cleans dispensing nozzles that dispense a sample or reagent using a rinse tank. The rinse tank includes first and second rinse liquid discharge ports arranged along the bottom and top of the rinse tank, respectively. The first rinse liquid discharge ports face the top of the rinse tank. The second rinse liquid discharge ports supply rinse liquid to flow to an exterior of the dispensing nozzles when aligned therewith. Each dispensing nozzle is rinsed by moving from a first position aligned with one of the first rinse liquid discharge ports to a second position aligned with one of the second rinse liquid discharge ports.