PROBLEM TO BE SOLVED: To properly improve the visibility of a blood vessel of an observation target.SOLUTION: This electronic endoscope system 76 includes a blue LD 66 and a bluish-purple LD 67, and simultaneously turns on the LDs. Laser light generated by the respective LDs 66, 67 is incident on a phosphor 43 to respectively generate white light having different spectra. A light intensity ratio adjustment part 77 controls the light emission amount ratio between the blue LD 66 and the bluish-purple LD 67 to adjust a spectrum as the whole of illumination light including the respective pieces of white light generated by the laser light of the respective LDs 66, 67. By the adjustment, the light intensity ratio adjustment part 77 reduces the contrast of a blood vessel of a non-observation target of a surface layer blood vessel and an intermediate deep layer blood vessel shown in a display image, and suppresses the display of the blood vessel of the non-observation target to the blood vessel of the observation target.
