An electronic endoscope apparatus capable of setting the brightness of a displayed spectroscopic image within a desirable range. The apparatus includes: a light source for irradiating white light on an observation target body a color imaging device for imaging the observation target image a first color conversion circuit for converting Y/C signals to RGB three color image signals a spectroscopic image generation circuit for generating a spectroscopic image from the RGB three color image signals a second color conversion circuit for converting the RGB three color image signals to Y/C signals a light amount regulation means for regulating the amount of white light irradiated on the observation target body and a light amount control circuit for controlling the light amount regulation means based on the luminance information provided by the Y/C signals outputted from the second color conversion circuit.
