Image evaluation method capable of objectively evaluating the image resolution of a microscope image. An image resolution method is characterized in that resolution in partial regions of an image is obtained over an entire area of the image or a portion of the image, averaging is performed over the entire area of the image or the portion of the image, and the averaged value is established as the resolution evaluation value of the entire area of the image or the portion of the image. This method eliminates the subjective impressions of the evaluator from evaluation of microscope image resolution, so image resolution evaluation values of high accuracy and good repeatability can be obtained.