PURPOSE: To make the random access of analytical items largely different in their reaction times possible by providing small washing groups separate from a main recirculation group.

CONSTITUTION: The different reaction times due to analytical items are adjusted by differentiating the recirculation number of times through a recirculation loop 2. Respective functional parts of a reaction tube removing part 6, an new reaction tube setting part 8, respective distribution parts 10, 12, 14, 16 of beads, a dilution liquid, a sample and a specimen and an absorbancy measuring part 18 are provided and, according to a built-in program, the treatment of each reaction tube 4 at the time of passage is individually selected to perform random accessing. A washing part 24 functions over continuous several steps simultaneously and arranged along a small loop 20 separate from the loop 2 and the reaction tube 4 required in washing is transferred to the loop 20 from the branch part 22a of the loop 2 and washed in the washing part 24 to be returned to the original position of the loop 2 at a confluent point 22b. By this method, in one reaction, the loop 2 is used so as to make one or more round and, in chemical analysis of a 1, 2 step method of two or three reactions and simple one reaction, one of respective function parts can be adapted.