PURPOSE: To obtain a fluorescent tube type down-light which can be mounted on the ceiling structured with narrow space inside the ceiling.

CONSTITUTION: A locking spring 7a is locked with an locking screw 7b, and mounting spring 9.9 are contracted inward with a stabilizer 3 held on the top of a frame 1. In this status, the stabilizer is inserted from a metal plate 6a side into its mounting pore. When the frame 1 is inserted to the depth, a stabilizer cover 3a hits a structure on the ceiling top because the ceiling back space is small. If the stabilizer cover is pushed up further in this status, it is pushed down, and the key-shaped tip end of the locking spring 7a is released from the locking screw 7b due to its restoration force. The frame 1 is removed once from its mounting hole from this status, and the stabilizer 3 is opened by the energizing force of a coil spring. Then a fluorescent tube type down-light is mounted. In this mounting status, since the two mounting springs 9 push the ceiling plate form the back, the down-light is not dropped.