To provide an automatic analyzer capable of shortening the time until an analysis result is outputted, and improving the reliability by suppressing dispersion of the measurement conditions.

This analyzer is equipped with a plurality of rotation heads for applying centrifugal force, having a component in the bottom part direction of reaction containers to a mixture of a specimen and a reagent inside the reaction containers, by rotating in the held state, the plurality of reaction containers filled near the bottom part with a carrier which generates a reaction image for determining the existence of flocculation, according to the result of a reaction, after the specimen is reacted with the reagent. Each of the plurality of rotation heads is to operate in a mutually independent manner.