A pressure signal process unit acquires data under a predetermined condition and a statistic distance between the acquired data and determination-purpose reference data stored in a storage unit is calculated. It is determined whether or not dispensing is abnormal and whether the determination-purpose reference data is suitable for an abnormality detection function to be properly fulfilled. If the determination-purpose reference data is not suitable for an abnormality detection function to be properly fulfilled, temporary determination-purpose reference data is prepared so as to be compared with the previously acquired data under a predetermined condition. If a difference therebetween is greater than a predetermined threshold value, a possibility that an automatic analyzer may have an abnormal component or that a failure may occur in the automatic analyzer is determined, and the result is transmitted to cause a display device to display an alarm.