To determine the stirring quality of a liquid in a reaction container by a simple constitution.

This autoanalyzer 1 is equipped with: a reagent dispensing mechanism 17 for dispensing the liquid (reagent) in the reaction container; a stirring device 23 which drives the surface elastic wave element 203 attached to the reaction container to produce a sonic wave and stirs the liquid (reaction liquid) in the reaction container by the sonic wave to react; and a measuring optical system 25 for measuring the spectral intensity in the reaction container, and is constituted so as to acquire the absorbance of the liquid in the reaction container. A coloring matter liquid analyzing processing part 41 is constituted so that the action of the respective parts of the autoanalyzer 1 is controlled in a predetermined timing to dispense a coloring matter liquid in the reaction container by the reagent dispensing mechanism 17 to be stirred in the reaction container by the stirring device 23, and the measurement by the measuring optical system 25 is subsequently performed to perform coloring matter liquid analyzing processing for acquiring the absorbance of the coloring matter liquid from the measuring result. A stirring quality determining part 43 is constituted so as to determine the quality of the stirring in a stirring position by the stirring device 23 on the basis of the absorbance of the coloring matter liquid acquired as the result of the coloring matter liquid analyzing processing.