An automatic analyzer for analyzing a sample by dispensing the sample and a reagent into a reaction container and using a reaction liquid combined in the reaction container, the automatic analyzer comprising: a reaction table configured to retain a plurality of the reaction containers along the circumference, wherein the reaction table is capable of rotating along the circumference; a photometry section configured to measure an absorbance of the reaction liquid in the reaction container a plurality of times at any one period of time the reaction container passes through a predetermined area with the rotation of the reaction table, which is performed every time the reaction container passes through the predetermined area; a standard deviation calculating section configured to calculate the standard deviation of a plurality of measured absorbances of the reaction liquid measured by the photometry section at any one period of time the reaction container passes through the predetermined area, which is performed every time the reaction container passes through the predetermined area; a standard deviation judging section configured to judge as to whether or not each of a plurality of the standard deviations calculated by the standard deviation calculating section does not exceed a threshold; an average value calculating section configured to calculate an average value for the plurality of measured absorbances for the reaction liquid having a standard deviation judged to not exceed the threshold by the standard deviation judging section; and an absorbance determining section configured to determine any one of a plurality of average values calculated by the average value calculating section to be absorbance for performing a sample analysis. a reaction table configured to retain a plurality of the reaction containers along the circumference, wherein the reaction table is capable of rotating along the circumference; a photometry section configured to measure an absorbance of the reaction liquid in the reaction container a plurality of times at any one period of time the reaction container passes through a predetermined area with the rotation of the reaction table, which is performed every time the reaction container passes through the predetermined area; a standard deviation calculating section configured to calculate the standard deviation of a plurality of measured absorbances of the reaction liquid measured by the photometry section at any one period of time the reaction container passes through the predetermined area, which is performed every time the reaction container passes through the predetermined area; a standard deviation judging section configured to judge as to whether or not each of a plurality of the standard deviations calculated by the standard deviation calculating section does not exceed a threshold; an average value calculating section configured to calculate an average value for the plurality of measured absorbances for the reaction liquid having a standard deviation judged to not exceed the threshold by the standard deviation judging section; and an absorbance determining section configured to determine any one of a plurality of average values calculated by the average value calculating section to be absorbance for performing a sample analysis.