PURPOSE: To simplify the mechanism for preparation and to increase the processing speed of a sample.

CONSTITUTION: A required number of empty containers 8 are laid out for each unknown sample in addition to a container 10 for an unknown sample, a standard sample, a reagent, a blank liquid, etc., on a turntable 6. An arm mechanism 14 with a sampling nozzle is laid out for sampling or injecting the sample on the turntable 6 and an agitation rod is provided at the tip of an arm mechanism 20 for mixing the sample which is infected to the empty container 8 with another liquid. The unknown sample, the standard sample, and the reagent are mixed and prepared in the empty container 8 by the standard addition method and are injected to an atomization part 4. Other empty containers are used for another preparation and the empty containers are not washed halfway during analysis.