An artificial illumination device for generating natural light similar to that from the sun and the sky includes a direct-light source; and a diffused-light generator, wherein the direct-light source includes a first light-emitting device configured to emit a primary light, and a first emitting surface positioned downstream the first light-emitting device, wherein the diffused-light generator is at least partially light-transparent and is positioned downstream of the first light-emitting device and includes a second emitting surface and is configured to cause diffused light at the second emitting surface. Both co-operate to form outer light at an outer emitting surface which includes a first light component which propagates along directions contained within the narrow peak and a second light component which propagates along directions spaced apart from the narrow peak, and wherein the first light component has a CCT which is lower than a CCT of the second light component.