An automatic analyzer comprising: means (104, 205) for registering in advance a quality control sample for a reagent of an analysis item to be measured in order to determine whether or not re-measurement of the calibration is recommended when the measured data of the quality control sample is out of a reference range between reference maximum and minimum values (308, 309); reference range setting means (104, 204) for setting in advance said reference range of measured data of the quality control sample having a known component; memory means; display means; and calibration setting means (104, 203) for setting in advance a calibration method to be executed as to said reagent of the analysis item, when data of the quality control sample being measured is not within said reference range, wherein said calibration setting means (104, 203) is adapted to set the calibration method in advance by selecting one of several combination patterns of standard samples used in calibration measurement characterised in that said calibration setting means (104, 203) is adapted to display recommendation information indicating the reason why said calibration method is recommended to be executed, said memory means, when the measured data of the quality control sample is not within the reference range, is arranged for storing the calibration method set by the calibration setting means (104, 203) together with information of the reagent of the analysis item being used, and said automatic analyzer further comprises a function of, when a measurement result of execution of the calibration method set by the calibration setting means (104, 203) is within an allowable range, deleting the recommendation information of the calibration method regarding the reagent of the analysis item used in the corresponding measurement. means (104, 205) for registering in advance a quality control sample for a reagent of an analysis item to be measured in order to determine whether or not re-measurement of the calibration is recommended when the measured data of the quality control sample is out of a reference range between reference maximum and minimum values (308, 309); reference range setting means (104, 204) for setting in advance said reference range of measured data of the quality control sample having a known component; memory means; display means; and calibration setting means (104, 203) for setting in advance a calibration method to be executed as to said reagent of the analysis item, when data of the quality control sample being measured is not within said reference range, wherein said calibration setting means (104, 203) is adapted to set the calibration method in advance by selecting one of several combination patterns of standard samples used in calibration measurement characterised in that said calibration setting means (104, 203) is adapted to display recommendation information indicating the reason why said calibration method is recommended to be executed, said memory means, when the measured data of the quality control sample is not within the reference range, is arranged for storing the calibration method set by the calibration setting means (104, 203) together with information of the reagent of the analysis item being used, and said automatic analyzer further comprises a function of, when a measurement result of execution of the calibration method set by the calibration setting means (104, 203) is within an allowable range, deleting the recommendation information of the calibration method regarding the reagent of the analysis item used in the corresponding measurement.