An illumination apparatus in an endoscopic system includes a light source unit having lasers with different peak wavelengths, the lasers being divided by peak wavelength into narrow band light source groups, a color imaging unit that detects the illumination color of illumination light, a memory that stores an appropriate illumination color for each narrow band light source group, an output calculator that, for each narrow band light source group, compares the illumination color obtained upon light emission by the lasers belonging to the narrow band light source group with the appropriate illumination color of the narrow band light source group and calculates an appropriate output for each of the lasers belonging to the narrow band light source group, and a light source controller that controls the lasers on the basis of the calculated appropriate output.