To provide a unit enhancing indoor illuminance to save electricity by easily leading sky light (brightness of the sky) into a room with little sunshine such as a multistory house, an office, a school, a factory, etc.

This unit consists of three components; a stainless steel light reflecting plate, a mounting frame fixed to a support such as a fence outside of the window or a window bar, and an angle adjusting arm with 45 angles of elevation. The unit of this invention is a horizontal skylight reflecting the sky light indoors and with which the same brightness as an old skylight can be obtained. Since it can be mass-produced from stainless steel and is half-unified, it is inexpensive and can be easily installed by an amateur.