Light is made more expressive by a simple configuration of an illumination device. An illumination device (10) includes: a projection section on which beams of light which beams are emitted from a first LED (1A) and a second LED (1B), respectively, are to be projected; and a light emission control section (3) configured to control the first LED (1A) and the second LED (1B) so as to temporally change intensities of the beams of light. The first LED (1A) and the second LED (1B) are provided so that the beams of light which beams are emitted from the first LED (1A) and the second LED (1B), respectively, overlap in part in the projection section, and assuming that a part of the projection section in which part the beams of light overlap is an overlapping part, the light emission control section (3) changes the intensities of the beams of light so that at least any one of a size, a location, and a shape of the overlapping part is temporally changed.