To provide an automotive dome light or room lamp, capable of eliminating use of a mold of a slide structure and preventing the sagging of a housing.

In the dome light 100 for the automobile where a lamp assembly 40 including a lens 10, the housing 20, and a bus bar 30 is assembled to a reinforce 60 through a roof panel 50 and which includes a resin clip 20C where the housing 20 engages with the circumferential edge 61 of the opening of the reinforce 60, the resin clip 20C is an inversed U-shaped elastomer comprised of a base 20B continuous with the housing 20, an inversed U-shaped part 20U continuous with the base 20B, a lock 20L continuous with the inversed U-shaped part 20U and forming a hook 20K, and an extension 20E continuous with the protruding piece 20T of the lower end of the lock 20L and further extending downward, the circumferential edge 51 of the opening of the roof panel 50 is made to be close to the extension 20E of the resin clip 20C while the resin clip 20C engages with the circumferential edge 61 of the opening of the reinforce 60.