PURPOSE: To provide higher efficiency and less manpower by automating dilution of samples, sampling to reaction tubes and dispensing of a reaction liquid.

CONSTITUTION: A nozzle 1 of a diluent dispenser 3 is gripped by a chuck of a rotor 1 and is moved. A specified volume of the sample soln. in a rack 2 is sucked up by the dispenser 3 which dispenses the diluting liquid into the empty sample tube. The nozzle of a sampling dispenser 4 is gripped by the chuck of the robot 1 and respectively prescribed volume of the dilute samples are drawn from the sample tubes after the end of the dilution in the rack 2 and are dispensed into the empty reaction tubes in a reaction vessel 5. The nozzle of any among the reaction liquid dispensers 6W8 is gripped by the chuck of the robot 1 and is moved to the aperture of the reaction tube in the reaction vessel 5 and the reaction liquid is dispensed from the reaction liquid dispenser into the dilute sample. The reaction tube in the reaction vessel 5 is gripped by the chuck of the robot 1 and is transferred to a 0preserving vessel 9 where the reaction liquid is preserved. The higher efficiency, less manpower and higher quantitative analysis characteristic are thereby obtd.