Linear luminaire extending in the longitudinal direction for a strip light, - whereby the luminaire has an elongated U-shaped support profile and an elongated U-shaped device support which is fixed on the support profile by interlocking, - whereby with a profile closing base the device support at least partially closes the support profile transversely with respect to the longitudinal direction, and as a result a profile inner space is formed in the support profile, - whereby the luminaire has at least one elongated optics cover which is fixed on the device support, - whereby the at least one optics cover closes the device support transversely with respect to the longitudinal direction, and as a result a support inner space is formed in the device support, - whereby the luminaire has at least one elongated luminaire support plate which has a plurality of light sources and is fixed in the support inner space of the device support, - whereby the device support has a luminaire support base which is arranged parallel and spaced apart from the profile closing base and extends in the longitudinal direction, and - whereby the luminaire support base divides the support inner space into a luminaire inner space with the at least one luminaire support plate and a heat insulating space which is arranged in the longitudinal direction between the profile inner space and the luminaire inner space, characterised in - that the profile closing base is formed integrally by two projections facing the support profile on the luminaire support base of the device support, whereby each projection has a T-shaped cross-section transversely with respect to the longitudinal direction and extends in the longitudinal direction. - whereby the luminaire has an elongated U-shaped support profile and an elongated U-shaped device support which is fixed on the support profile by interlocking, - whereby with a profile closing base the device support at least partially closes the support profile transversely with respect to the longitudinal direction, and as a result a profile inner space is formed in the support profile, - whereby the luminaire has at least one elongated optics cover which is fixed on the device support, - whereby the at least one optics cover closes the device support transversely with respect to the longitudinal direction, and as a result a support inner space is formed in the device support, - whereby the luminaire has at least one elongated luminaire support plate which has a plurality of light sources and is fixed in the support inner space of the device support, - whereby the device support has a luminaire support base which is arranged parallel and spaced apart from the profile closing base and extends in the longitudinal direction, and - whereby the luminaire support base divides the support inner space into a luminaire inner space with the at least one luminaire support plate and a heat insulating space which is arranged in the longitudinal direction between the profile inner space and the luminaire inner space, characterised in - that the profile closing base is formed integrally by two projections facing the support profile on the luminaire support base of the device support, whereby each projection has a T-shaped cross-section transversely with respect to the longitudinal direction and extends in the longitudinal direction.