A room lamp which is cost effective and simple. The room lamp has a design part and a function part, the design part being secured with a lens in a housing attachable to an opening defined in an interior finish material of a vehicle, and the function part being disposed at a side of a rear face of the interior finish material in that the function part is supported by the design part, and having a light source. Clips are provided in the housing for temporarily securing the design part at predetermined positions. Projections project from the edge part of the opening along the rear face of the interior finish material. The housing and the projections hold the interior finish material.