PURPOSE: To improve the accuracy and reproducibility of inspected and measured data in an automatic blood corpuscle sorting apparatus and handle the disease and blood corpuscle mode numerically with respect their relation by simultaneously inspecting red and white blood corpuscles and blood plate in one automated apparatus in parallel.

CONSTITUTION: The optical axis of the blood corpuscle image of a microscope 10 is divided itno three optical paths by half mirrors or dichroic mirrors 15, 16 and reflecting mirrors 17, 18, etc. to thus focus the images of the corpuscles on the screen of an image sensor 11 through color filters 19, 20, 21 for intensifying the red and white blood corpuscles and blood plate. Three signals are applied from blood corpuscle image input unit through a color signal processor 25 for separating the signals into two of white and red blood corpuscle areas and a cell extractor 23 having a threshold determining circuit 26 for further separating the white blood corpuscle region into white blood corpuscle nucleus region (including blood plate) and cellular region to memory 27 and arithmetic circuits 28, 29.