An illumination apparatus, which is to be connected to a light source apparatus that generates laser light and which is to be attached to an optical cable that guides the laser light, is provided. The illumination apparatus includes a light-emitting module which is to be attached to a tip portion of the optical cable. The light-emitting module receives the laser light emitted from the optical cable, converts the laser light into light having a different wavelength of a predetermined color, and emits the light. A heat dissipating lens case includes a lens and dissipates heat generated by the light-emitting module. The lens controls distribution of the light emitted by the light-emitting module. The heat dissipating lens case includes an attachment structure which allows the heat dissipating lens case to be removably attached to the light-emitting module.