To provide a luminaire allowing the at-site execution of works by adjusting the overlapped portion of lamps one over another simply.

Parts near one diagonal of an approximately rectangular shape are recessed to form recesses 5, and parts with the other diagonal are formed as projections 2, and a lamp is fitted in a socket 3 installed near the forefront of each projection 2 in such a way as tracing the direction of tying together other projections 2, and the projection 2 on the adjacent luminaire body 1 is positioned as mating with the recess 5 and a plurality of such luminaire bodies 1 are installed continuously so that an intended luminaire is accomplished, wherein a locating means 4 locates adjoining luminaire bodies 1 relative to each other at least about their longitudinal direction using the recess 5 in one luminaire body 1 and the other luminaire body 1.