An electronic endoscope apparatus capable of displaying a section irradiated by near infrared light within a display image in a visually recognizable manner, even when used in combination with a near infrared light irradiation unit without aiming light. A RBG image is obtained by imaging a target observation area through a CCD imaging device. The IR image signal generation circuit (29) calculates an IR image signal constituted by an estimated value of reflected light intensity of the near infrared light by performing a matrix operation on the RGB image signal using estimated matrix data for estimating the reflected light intensity of the near infrared light, and spectral matrix data of the near infrared light. The mode selector directly outputs the R and G signals as Rs and Gs signals, and as for a Bs signal, it outputs an image signal including the B and IR signals superimposed with each other. The monitor 52 displays a color signal based on the RS, Gs and Bs signals.
