An illumination device includes a light source configured to emit laser light, a transmission part configured to transmit the laser light emitted from the light source, and a lighting appliance configured to convert a wavelength of the laser light transmitted through the transmission part and to emit illumination light. The transmission part includes a rail-shaped guide part extending in a linear shape along a transmission direction of the laser light. The lighting appliance is configured to be mounted in an arbitrary position of the guide part.