In determining whether a rack inputted to the automatic analyzer by the user is to be transferred to an analysis section or not, samples existing in a route from a buffer to a sample dispensing position in the analysis section are identified, and the number of items in which suction by a nozzle has not been completed in analysis items requested for the samples is managed. When the number of items is reduced to be smaller than a given number, the conveyance of a next rack from the buffer to the analysis section is controlled, thereby limiting the number of analysis items requested for samples in a waiting state for analysis in the analysis section constantly to be smaller than a fixed number. As a result, a period of time until a measurement result of emergency samples is outputted can be reduced even when emergency samples are newly inputted.