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 (14, 17) 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 (14, 17) 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.