Disclosed is an automated liquid-phase immunoassay apparatus used with a cuvette having a plurality of chambers containing a reagent necessary for detection of an analyte in a biological specimen. The apparatus includes a movable cuvette module equipped with the cuvette, an optical reading module for optical assaying of a material resulting from a reaction between the specimen and the reagent, and a dispenser module which is positioned on the cuvette module and which dispenses the specimen and the reagent to the plurality of chambers of the cuvette and washes the specimen and the reagent therefrom.