An illumination apparatus includes a surface rim, a rotation ring, a light holder and a retractable tube. The surface rim has a rim cover, and a rim wall protruding from the rim cover and defining a light opening. The rotation ring is held by the rim wall to be rotatable along an axis of a center of the light opening. The light holder is used for support a light source. The light holder is fixed to the rotation ring by two rotation axles so that the light holder is capable of orienting a light source in a plurality of angles with respect to a plane of the rotation ring. The retractable tube has an optical cover, such that a distance between the optical cover and the light source is adjustable.