An electronic endoscope apparatus is provided and includes: a light source that illuminates a subject with white light; a color imaging device that takes an image of the subject illuminated with white light; and a spectral-image forming circuit that operates RGB three color image signals based on an output from the color imaging device and a matrix data to generate an spectral image signal representative of a spectral image in a color at a designated wavelength. The spectral-image forming circuit is adapted to generate spectral image signals representative of spectral images in respective colors at least three wavelengths different from one another.