PURPOSE: To make quick mixing and stirring operation of a reagent and specimen after dispensing of the specimen by constituting the titled device in such a manner that sample dispensing to stir a liquid mixture composed of the specimen and reagent can be executed simultaneously when the specimen is dispensed into a specimen housing hole.

CONSTITUTION: The latex reagent and buffer soln. are sucked by a reagent pipetter and is dispensed into the specimen housing hole 41. A pipette 74 and stirring bar 82 are simultaneously inserted into the specimen housing hole 41 and the discharge of the specimen is executed when the specimen housing hole 41 contg. the reagent is brought to the sample dispensing position by step rotation. The stirring bar 82 is rotated by a motor 81 at the same instant, by which the specimen and latex reagent are stirred and mixed. The quick mixing and stirring operation after the specimen dispensing is thus executed and since the progression of the reaction is made uniform, this device is adequate for the automatic analysis to make quick optical measurement of the reaction condition.