A method of obtaining a quantum efficiency distribution in a predetermined sample surface, including: irradiating a reference material with excitation light belonging to a first wavelength range; obtaining the reference material's image, which includes a first channel for the first wavelength range and a second channel for a second wavelength range, the first and the second channel's irradiation luminance value in each pixel; irradiating the predetermined sample surface with the excitation light; obtaining the first and the second channel's measurement luminance value in each pixel of the image of the predetermined surface; calculating an absorption luminance value from a difference between the first channel's irradiation luminance value and measurement luminance value; calculating a fluorescence luminance value from difference between the second channel's irradiation luminance value and measurement luminance value; calculating quantum efficiency of each pixel based on the values; and obtaining quantum efficiency distribution.