Provided is an illumination device comprising a support structure and a light-emitting component being provided on one side of the support structure. The support structure also has an opening on one of its sides and an optical component cooperating with the opening to form an accommodating space. The illumination device also comprises an integrally formed light transmission portion provided above a light-emitting side of the light-emitting component. The light transmission portion is configured to transmit light from the light-emitting component. The illumination device additionally comprises a plurality of sealing portions being integrally formed.