A conventional flow type particle analysis apparatus could not detect both a human error, such as leaving behind a sample, a shortage of the sample, or a shortage of a reagent, and an abnormality of a flow path system by an inexpensive and simple method. A particle analysis apparatus according to the present invention includes means that perform processes upon image processing of images (110) acquired in a measurement of the sample, simultaneously with a normal image processing for classifying target particles. The means included are: image processing means (110a) for calculating information of RGB density distributions of each whole image; abnormal state determination processing means (110c) for determining whether or not the acquired images are in an abnormal state according to tendencies of the RGB density distributions; and an abnormality judgment process means for making final determination of the existence of an abnormality by calculating an appearance frequency of abnormal images after all measurements for the one sample is completed. These means allow diagnosis of abnormalities to be conducted simultaneously with normal analysis without changing the configuration of the conventional apparatus.