PROBLEM TO BE SOLVED: To provide an endoscope system which can display an appropriate image that does not cause any disadvantage to a user in order to observe a fine blood vessel of a surface layer tissue or a microstructure even while the system does not start until narrow band light becomes stable in switching a mode from a normal light mode to perform normal observation to a narrow band light mode to perform special light observation.SOLUTION: In switching a mode from a first mode to a second mode, a calibration part corrects light emission intensity in a second light source part on the basis of spectral reflectance data of an object of photography spectral-estimated by using first photography image information obtained by imaging the object of photography by using first emitted light from the first light source part at an imaging part in the first mode and a blue (B) signal value and a green (G) signal value obtained from second photography image information obtained by switching to the second mode and imaging the object of photography by using at least a second emission light from the second light source part.
