There is provided an illumination device that is prevented from being increased in size. The illumination device includes a first light source, a second light source, a main capacitor configured to store electric charge for causing the first light source and the second light source to emit light, a first coil electrically connected between the first light source and the main capacitor, and a second coil electrically connected between the second light source and the main capacitor. A radial direction of the first coil and a radial direction of the second coil are parallel to a vertical direction of the illumination device, the first coil and the second coil are aligned with the main capacitor in a horizontal direction of the illumination device, and the first coil is aligned with the second coil in a direction orthogonal to the horizontal direction of the illumination device.