PURPOSE: To automate the analyzing stage of liquid in μl unit by performing automatically operations such as centrifugal sepn. of samples in reaction vessels, reagent injection, drying, temp. change and mixing by means of a sequence controller.

CONSTITUTION: A rotary table 4 having plural reaction vessels 3 in the peripheral end part thereof is mounted rotatably to a centrifugal separator 1, and a detecting part 6 for detecting the rotating position of the table 4 is provided. A holding body 9 having a reagent discharging nozzle 7, a suction nozzle 8 for drying and a cover attaching and detaching device 30 for the reaction vessels is disposed; a thermostatic chamber which has a thermostat 14 and a mixer 15 and is freely movable in the fulcrum axis direction thereof as well as a mixer lifting device 17 are provided and further a sequence controller 26 for controlling the operation of the nozzles 7, 8, and the devices 1, 30, 17 is installed. The cover is automatically attached and detached to and from the vessel 3 by the device 30 in order to prevent the scattering or evaporation of the liquid therein.