A display device includes a substrate including a display area and a peripheral area. A display element is disposed in the display area and is electrically connected to a thin film transistor. A power supply line is disposed in the peripheral area. An insulating layer covers a portion of the power supply line. A barrier layer is disposed on the insulating layer and includes a first side surface facing the display area and a second side surface facing away from the display area. At least one of the first side surface or the second side surface includes a concavo-convex surface. The barrier layer forms a step difference with respect to an upper surface of the insulating layer. An end of the insulating layer is positioned beyond the second side surface of the barrier layer on a side of the barrier layer facing away from the display area.