To provide a portable inclined illumination apparatus superior in energy saving and capable of obtaining illumination efficient and suitable for makeup.

A portable oblique illumination device U does not dazzle use's eyes even if the illumination device is placed faceup on a desk because of directional surface emission illumination. Owing to this, even with a user holding a mirror MR opposite to a user face UF, the mirror MR does not obstruct the illumination since the user's face UF is illuminated from obliquely downward. Furthermore, the entire user's face UF can be illuminated without casting a shadow on the user's face UF.