An automatic analysis device comprising: a reactor vessel ; a reaction disk configured to hold the reactor vessel ; a sample dispensing mechanism configured to dispense a sample into the reactor vessel ; a reagent dispensing mechanism configured to dispense a reagent into the reactor vessel ; an optical system including a light source configured to emit light onto a mixture of the sample and the reagent dispensed into the reactor vessel , and a detector configured to detect the light emitted from the light source ; and a washing mechanism configured to wash the reactor vessel , wherein the automatic analysis device is configured to analyze the sample based on the light detected by the detector , the washing mechanism includes: a washing liquid supply nozzle configured to supply a washing liquid to the reactor vessel after the analysis; a first washing liquid suction nozzle configured to suction the supplied washing liquid ; and a washing tip-equipped second washing liquid suction nozzle provided with a washing tip on a bottom end of the nozzle , characterized in that the washing tip includes three or more rectangular parallelepipeds having different cross-sectional areas, including an upper portion , a lower portion , and an intermediate portion located between the upper portion and the lower portion , and the rectangular parallelepiped on the upper portion has the maximum cross-sectional area, and the rectangular parallelepiped on the lower portion has a smaller cross-sectional area than the rectangular parallelepiped on the upper portion , and the rectangular parallelepiped on the intermediate portion has the minimum cross-sectional area. a reactor vessel ; a reaction disk configured to hold the reactor vessel ; a sample dispensing mechanism configured to dispense a sample into the reactor vessel ; a reagent dispensing mechanism configured to dispense a reagent into the reactor vessel ; an optical system including a light source configured to emit light onto a mixture of the sample and the reagent dispensed into the reactor vessel , and a detector configured to detect the light emitted from the light source ; and a washing mechanism configured to wash the reactor vessel , wherein the automatic analysis device is configured to analyze the sample based on the light detected by the detector , the washing mechanism includes: a washing liquid supply nozzle configured to supply a washing liquid to the reactor vessel after the analysis; a first washing liquid suction nozzle configured to suction the supplied washing liquid ; and a washing tip-equipped second washing liquid suction nozzle provided with a washing tip on a bottom end of the nozzle , a washing liquid supply nozzle configured to supply a washing liquid to the reactor vessel after the analysis; a first washing liquid suction nozzle configured to suction the supplied washing liquid ; and a washing tip-equipped second washing liquid suction nozzle provided with a washing tip on a bottom end of the nozzle , characterized in that the washing tip includes three or more rectangular parallelepipeds having different cross-sectional areas, including an upper portion , a lower portion , and an intermediate portion located between the upper portion and the lower portion , and the rectangular parallelepiped on the upper portion has the maximum cross-sectional area, and the rectangular parallelepiped on the lower portion has a smaller cross-sectional area than the rectangular parallelepiped on the upper portion , and the rectangular parallelepiped on the intermediate portion has the minimum cross-sectional area. <EOS>