Provided is a high decorative illumination device that utilizes a lenticular lens sheet. An illumination device includes a lenticular lens sheet and an LED light source. The lenticular lens sheet is curved in an X direction, and a convex surface is formed in a concave shape. The LED light source is positioned inside the convex surface of the lenticular lens sheet. First and second reflection components from first and second bright points which are acquired by reflecting irradiation light rays from the LED light source from plano-convex cylindrical lenses are incident on left and right eyes of an observer who observes the illumination device. The observer observes a virtual image as if a light emitter is present in a position in which the first and second reflection components cross each other.