A display device includes: a plurality of control lines; a plurality of power supply lines; a plurality of data signal lines; an oxide semiconductor layer; a first metal layer; a gate insulation film; a first inorganic insulation film; a second metal layer; a second inorganic insulation film; and a third metal layer. The oxide semiconductor layer, in a plan view, contains therein semiconductor lines formed as isolated regions between a plurality of drivers and a display area. The semiconductor lines cross the plurality of control lines and the plurality of power supply lines, are in contact with the plurality of control lines via an opening in a gate insulation film, are in contact with the plurality of power supply lines via an opening in the first inorganic insulation film, and have a plurality of narrowed portions, such that thicker and thinner regions exist along the same line.