The prior art automotive room lamp assembly has a problem that the designing and manufacturing of a variety of room lamp assembly including a large-sized or a small-sized one depending on the type of vehicle model inevitably involves a small lot production which entails the rise in the cost as well as the storage of many types of parts which again invites the rise in cost. The automotive room lamp assembly is composed of a housing 4 accommodating a lamp 42 in the recess 41 therein; a framework formed with a flange 51 to be secured on the periphery of said housing and having different sizes; and a lamp to be mounted onto the flange 53 of said framework.