ILLUMINATION DEVICE

PROBLEM TO BE SOLVED: To provide an illumination device having a lights-out function which is more convenient than the conventional ones.SOLUTION: An illumination device 1 comprises a light source unit 31 for illumination which allows for continuous change of optical output and a control unit 20 which controls the optical output by the light source unit 31 for illumination. The control unit 20 controls the optical output by the light source unit 31 for illumination according to an operation mode selected by an operator. When a prescribed extinction control mode is selected as the operation mode, the control unit 20 continuously decreases the luminous flux emitted from the light source unit 31 for illumination to a first value during a first period, keeps the first value during a next second period, and further decreases the luminous flux from the first value during a next third period.