To make hard the generation of contact error between metal caps and power feeder terminals.

This luminaire has a double cap type electric bulb equipped with a filament 2 in a air-tight container 1. The filament 2 is connected to metal caps on both outer ends of the container 1 through lead member 3. The caps 4 has each a thinner tip 4d than a base part 4a and a planar part 4c crossing the axis of filament on the intermediate part. This luminaire has also a pair of power feeder terminals 5 having opposite planer parts abutting against the planar part 4c of the cap 4. The paired terminals 5 are mounted on a base 6.