A display device comprising: a substrate comprising a pixel region and a peripheral region; pixels in the pixel region of the substrate, the pixels comprising at least one transistor and a light emitting device (OLED) connected to the transistor; data lines and scan lines connected to the pixels; and a power line to supply power to the light emitting device (OLED), the transistor comprises an active pattern on the substrate, source and drain electrodes each connected to the active pattern, a gate electrode on the active pattern with a gate insulating layer interposed therebetween, an interlayer insulating layer covering the gate electrode, the interlayer insulating layer comprising a first interlayer insulating layer, a second interlayer insulating layer, and a third interlayer insulating layer, which are sequentially stacked, and a protective layer on the interlayer insulating layer, wherein the power line comprises a first conductive layer parallel to the data line, the first conductive layer on the second interlayer insulating layer, and a second conductive layer connected to the first conductive layer, wherein the second conductive layer includes a plurality of first conductive lines and a plurality of second conductive lines crossing the first conductive lines, and the first conductive lines overlaps with the first conductive layer in parallel to the first conductive layer, and wherein the third interlayer insulating layer comprises a concave part in a region in which the light emitting device (OLED) and the second conductive layer overlap with each other, and the second conductive layer is in the concave part characterized in that the concave part comprises a region in which a portion of the third interlayer insulating layer is removed and the protective layer is provided on the second conductive layer. a substrate comprising a pixel region and a peripheral region; pixels in the pixel region of the substrate, the pixels comprising at least one transistor and a light emitting device (OLED) connected to the transistor; data lines and scan lines connected to the pixels; and a power line to supply power to the light emitting device (OLED), the transistor comprises an active pattern on the substrate, source and drain electrodes each connected to the active pattern, a gate electrode on the active pattern with a gate insulating layer interposed therebetween, an interlayer insulating layer covering the gate electrode, the interlayer insulating layer comprising a first interlayer insulating layer, a second interlayer insulating layer, and a third interlayer insulating layer, which are sequentially stacked, and a protective layer on the interlayer insulating layer, wherein the power line comprises a first conductive layer parallel to the data line, the first conductive layer on the second interlayer insulating layer, and a second conductive layer connected to the first conductive layer, wherein the second conductive layer includes a plurality of first conductive lines and a plurality of second conductive lines crossing the first conductive lines, and the first conductive lines overlaps with the first conductive layer in parallel to the first conductive layer, and wherein the third interlayer insulating layer comprises a concave part in a region in which the light emitting device (OLED) and the second conductive layer overlap with each other, and the second conductive layer is in the concave part characterized in that the concave part comprises a region in which a portion of the third interlayer insulating layer is removed and the protective layer is provided on the second conductive layer.