An image measurement device including: light sources that irradiate light beams having different peak wavelengths; a staining method obtaining unit which obtains information indicating a staining method of an inspection specimen; an image obtaining unit which: selects a combination of light sources according to the staining method, based on illumination information; and capture inspection images of the inspection specimen with light beams from the selected light sources, and capture reference images of a reference specimen with light beams from the respective light sources; a calculating unit which calculates a positivity based on the inspection images; and an evaluation unit which associates the staining method of the reference specimen with the combination of light sources to generate the illumination information based on a total value of coefficients in a linear sum of the ortho-normalization base vectors of a spectral distribution of light sources calculated based on the reference images.