To enhance physical the coupling strength of a thin lamp relative to a lamp holder, while not hampering the advantage of a single-action attaching and detaching operation, in a thin lighting system with a structure having the thin lamp made detachable relative to a lamp holder.

The thin lamp 100 consists of an anode 11, having a phosphor 10 formed on its inner surface, an electron emission cathode 12 facing it, and a translucent enclosure 13. The translucent enclosure 13 of the thin lamp 100 is engaged with a holder body 21 and an engagement cylindrical part 22 of the lamp holder 200, and the connecting terminals 14, 15 of the thin lamp 100 are connected to the feeder terminals 24, 25 of the lamp holder 200. They are fitted by a single-action operation. A magnetic body 16, attached to the translucent enclosure 13, is held strongly to a magnet 26 attached to the lamp holder 200 by magnetic attraction force. They are uncoupled with a single-action operation by using an uncoupling tool 27 having boosting action.