An array substrate includes an almost rectangular effective portion which is formed on the major surface of the substrate and includes a plurality of pixels for displaying images. An organic EL display device includes a sealer which is placed to cover at least the effective portion on the major surface of the array substrate. The sealer has a structure in which at least two almost rectangular buffer layers which have substantially the same pattern and barrier layers each of which is a pattern larger than each buffer layer and covers each buffer layer to shield it from the open air are stacked on each other. The shortest distance from one side of an end of the effective portion to one side of an end of the first buffer layer is different from the shortest distance to one side of an end of the second buffer layer.