A pathological diagnosis assisting apparatus according to the present invention includes an image classification unit configured to classify at least one type of a specific substance, a tissue area extraction unit configured to extract a tissue area in the image of the sample, an image dividing unit configured to divide the tissue area into a plurality of sections, a specific substance occupancy rate calculation unit configured to, calculate an occupancy rate of the at least one type of the specific substance in each of the plurality of sections, and a diagnosis assisting information providing unit configured to determine an intermediate value of the occupancy rate of the specific substance from the calculated occupancy rates of the plurality of sections and to provide the intermediate value as the diagnosis assisting information.