An illumination device includes a light source module consisting of a substrate and a plurality of light emitting elements on the substrate in an array and an optical module array consisting of a plurality of optical modules covering the light emitting elements. Each optical module includes a first optical component and a second optical component. A first illumination distribution pattern is generated by light from the light emitting elements and modulated by the first optical components. A second illumination distribution pattern is generated by light from the light emitting elements and modulated by the second optical components. An illumination distribution pattern of the illumination device is superposition of the first illumination distribution pattern and the second illumination distribution pattern.