PURPOSE: To prevent a measurement from being taken in an unsteady state originating from turbidity by calculating a light absorbance increment based upon the turbidity in liquid to be measured on the basis of the scatter degree of measurement light, and deciding that a light absorbance range should be corrected or that the calculated value is within a proper range from the calculated value.

CONSTITUTION: Variation in the light absorbance of the liquid 4 to be measured between a light source 2 and a photodetector 3 is measured within the proper absorbance range of a storage part 6, and a specific component is measured on the basis of the calibration value in the storage part 6 and displayed at a display part 9. In this case, the absorbance increment due to the turbidity of the liquid 4 is calculated by the 1st arithmetic part 7 on the basis of the difference between outputs of absorbance with and without a slid between the liquid 4 and the photodetector 3, and the proper absorbance range in the storage part 6 is corrected by the 2nd arithmetic part 8. Further, a sample is sampled with a sample pipet 19 and dispensed to a reaction vessel 41, and the 1st and the 2nd reaction liquids 17 and 18 are added to the 1st and the 2nd reaction sample dispensation positions in the vessel 41 and transported to a photometric position corresponding to the liquid 4.