An illumination device is provided. The illumination device includes a lamp body, a stage, at least one first light source, a first radiator, and a first feed conductor. The stage is disposed in the lamp body. The first light source is disposed on the stage. The first opening is formed on the first radiator, the first light source corresponds to the first opening, and the first radiator transmits a first wireless signal. The first feed conductor is connected to the first radiator.