To provide a dielectric barrier discharge lamp excelling in a heat radiation property and capable of miniaturizing a lighting system; and to provide a flat lighting system using the dielectric barrier discharge lamp.

A first discharge electrode 23 is arranged on the outside surface of a lid body 20 of a sealed vessel 21 with a discharge space 22 formed therein, and a second discharge electrode 24 is arranged on the outside surface of a bottom part of a vessel body 18. The second discharge electrode 24 side of the vessel body 18 is stuck on a chassis 11 made of a metal excelling in heat conductivity through a jointing material layer 17 formed out of a thermally-conductive material such as a thermally-conductive epoxy resin adhesive. The chassis 11 forms the back face side of a case 14 of the flat lighting system 10 for housing this dielectric barrier discharge lamp 15 and a driving circuit 16.