An illumination device includes an excitation light source which emits excitation light, a wavelength converter which generates fluorescent light having a wavelength different from that of the excitation light through the excitation of the excitation light and a light path-splitting member including a first filter and a second filter arranged to alternately come across a light path of the excitation light, wherein the first filter reflects one of the excitation light and the fluorescent light and transmits the other of the excitation light and the fluorescent light, the second filter transmits light reflected by the first filter and reflects light transmitted through the first filter, and the wavelength converter is disposed in a reflection light path or a transmission light path of the excitation light.