The hematocrit plate counting method, a counting method frequently applied in the past to count the number of blood cells, is often applied to count blood cells such as white blood cells and red blood cells. In addition to counting blood cells, it can also be used in the technique of pathogenic microorganisms such as yeast and bacteria. The blood cell counting plate is divided into a number of grid-like structures by microscopy, and then a proper dilution of blood is performed for counting, and the number of various blood cells is finally calculated. This was a commonly used method in the past, but in recent years, basically, fully automated blood cell analyzers are used to count the number of various blood cells, to achieve the purpose of fast and accurate. Nowadays, the blood cell counting plate counting method is seldom used anymore, because with a fully automated blood cell analyzer, the number of various blood cells, including red blood cells, white blood cells, platelets, etc., can be accurately counted, thus providing useful information for clinical purposes.