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 transmit light in the predetermined band from the light source 2 while reflecting light that is 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.
