PROBLEM TO BE SOLVED: To provide an endoscope system which prevents disadvantage to a user even during a period when a narrow band light mode is not started till the stabilization of narrow band light in a case where a normal light mode for normal observation is changed into a narrow band light mode for special light observation, and also which displays and provides to the user, an image appropriate for the observation of fine vessels or fine structures in a surface tissue.SOLUTION: A calibration part corrects the light emission intensity of a second light source part, on the basis of spectral reflectance data of an image pickup object which is spectroscopically estimated by using first picked-up image information obtained by imaging the image pickup object by an imaging part through the use of first emission light from a first light source part in a first mode when the first mode is changed over into a second mode, and also on the basis of a blue (B) signal value and a green (G) signal value which are obtained from second picked-up image information obtained by imaging the image pickup object by the imaging part through the use of at least second emission light from the second light source part after the changeover into the second mode.
