An automatic analysis device comprising: a sample pipetter which dispenses a sample to be measured into a reaction cell, the sample being stored in a sample bottle; a reagent pipetter which dispenses a reagent stored in a reagent bottle into the reaction cell; a measurement unit which measures, for each of a plurality of measurement items for the sample, absorbance of a respective liquid mixture of the sample and a respective reagent dispensed into a respective reaction cell as a measurement value; and a data processing device comprising: an approximation formula storage unit which stores an approximation formula representing the time-variation of measurement values regarding each of measurement items and parameters specifying the approximation formula in regard to each measurement item; a factor storage unit which stores each factor previously specified as a factor that could affect measurement accuracy as a cause of abnormality of the measurement items, while associating each factor with each measurement item; an abnormality judgment unit which judges the presence/absence of an abnormality in the measurement values of each measurement item on the basis of the approximation formula and the parameters of the approximation formula; a factor judgment unit which reads out results of the judgment of the presence/absence of an abnormality in the measurement values of each measurement item by the abnormality judgment unit in a preset order, and judges as an abnormality factor cause of the abnormality of a measurement item a factor stored in the factor storage unit in association with the measurement item in a case where the results of the judgment of the presence/absence of an abnormality in the measurement values of each measurement item by the abnormality judgment unit read out in the preset order include a plurality of consecutive results that indicate the presence of an abnormality; and a notification unit which notifies an operator of the abnormality factor on the basis of the result of the judgment by the factor judgment unit. a sample pipetter which dispenses a sample to be measured into a reaction cell, the sample being stored in a sample bottle; a reagent pipetter which dispenses a reagent stored in a reagent bottle into the reaction cell; a measurement unit which measures, for each of a plurality of measurement items for the sample, absorbance of a respective liquid mixture of the sample and a respective reagent dispensed into a respective reaction cell as a measurement value; and a data processing device comprising: an approximation formula storage unit which stores an approximation formula representing the time-variation of measurement values regarding each of measurement items and parameters specifying the approximation formula in regard to each measurement item; a factor storage unit which stores each factor previously specified as a factor that could affect measurement accuracy as a cause of abnormality of the measurement items, while associating each factor with each measurement item; an abnormality judgment unit which judges the presence/absence of an abnormality in the measurement values of each measurement item on the basis of the approximation formula and the parameters of the approximation formula; a factor judgment unit which reads out results of the judgment of the presence/absence of an abnormality in the measurement values of each measurement item by the abnormality judgment unit in a preset order, and judges as an abnormality factor cause of the abnormality of a measurement item a factor stored in the factor storage unit in association with the measurement item in a case where the results of the judgment of the presence/absence of an abnormality in the measurement values of each measurement item by the abnormality judgment unit read out in the preset order include a plurality of consecutive results that indicate the presence of an abnormality; and a notification unit which notifies an operator of the abnormality factor on the basis of the result of the judgment by the factor judgment unit. an approximation formula storage unit which stores an approximation formula representing the time-variation of measurement values regarding each of measurement items and parameters specifying the approximation formula in regard to each measurement item; a factor storage unit which stores each factor previously specified as a factor that could affect measurement accuracy as a cause of abnormality of the measurement items, while associating each factor with each measurement item; an abnormality judgment unit which judges the presence/absence of an abnormality in the measurement values of each measurement item on the basis of the approximation formula and the parameters of the approximation formula; a factor judgment unit which reads out results of the judgment of the presence/absence of an abnormality in the measurement values of each measurement item by the abnormality judgment unit in a preset order, and judges as an abnormality factor cause of the abnormality of a measurement item a factor stored in the factor storage unit in association with the measurement item in a case where the results of the judgment of the presence/absence of an abnormality in the measurement values of each measurement item by the abnormality judgment unit read out in the preset order include a plurality of consecutive results that indicate the presence of an abnormality; and a notification unit which notifies an operator of the abnormality factor on the basis of the result of the judgment by the factor judgment unit.