An evaluation system includes a capture unit for capturing an image of a living tissue in which HER2 protein and cell nucleuses are dyed, a discrimination unit for identifying a cell membrane from the image of the living tissue based on dyed cell nucleuses within the image of the living tissue captured by the capture unit to discriminate a dyed state of the cell membrane, and an evaluation unit for evaluating development of the HER2 protein based on a discrimination result by the discrimination unit.