Provided is an illumination apparatus that can switch between at least two illumination modes having different spectral characteristics in a short period of time.The illumination apparatus includes light sources 1 and 2 configured to generate light in wavelength bands required for at least two illumination modes a dichroic mirror 5 configured to transmit light in a predetermined band from the light source 1, to reflect light from the light source 2 outside the predetermined band in the direction of the optical axis of light from the light source 1, and to combine the light from the light source 1 and the light from the light source 2 and a control unit configured to control the illumination states of the light sources 1 and 2.
