To reduce the cost while improving the outward appearance by arranging a luminaire so that it does not stand out.

This luminaire under a shelf has light body 4 to which a long lamp is fitted and a lighting device part 3 with a lighting device 3a which is connected to the light body 4 and turns on the lamp, and is fitted to a lower surface of a shelf plate 2 which is built between a pair of brackets 1 installed laterally with a designated interval. While the light body 4 is installed on a lower side of the front of the shelf plate 2, the lighting device part 3 is installed on a lower side of the rear of the shelf plate 2, and one end of the lighting device part 3 is engaged with the bracket 1 and the other end is engaged and fitted to a long member 7 built between the pair of brackets 1.