An illumination device includes a main body unit, a light source module and a cover unit. The light source module is disposed in an upper space of the main body unit to be separated therefrom and includes a substrate and at least one light emitting device respectively disposed on both surfaces of the substrate. The cover unit is disposed on the main body unit to cover the light source module and allowing light emitted from the light source module to be emitted from a surface of the cover unit in a radial manner.