To provide a technique for displaying a desired form more clearly and definitely, in displaying the form in a light emitting region in an organic EL panel.

A heat-equalizing sheet 10 with a desired form is disposed on the rear face (on a sealing layer) on a side opposite to the light emitting face, of an organic EL panel. A light emitting region 15 includes a heat-equalized region 16 where the heat-equalizing sheet 10 is disposed on a rear-face side and a heat-nonequalized region 17 surrounding the heat-equalized region 16. A temperature distribution is nonuniform in a boundary region along a boundary line between the heat-equalized region 16 and the heat-nonequalized region 17, the boundary region being a part of the heat-nonequalized region 17. A form of the heat-equalizing sheet 10 is displayed within the light emitting region 15, during the light emitting region 15 emits light.