A display device is reduced in size. Wiring lines are formed in a portion of a pixel substrate which is covered with a sealing member. The width of each of the wiring lines is set to a width that allows the sealing member on the wiring lines sufficient exposure to ultraviolet rays when the sealing member is irradiated with ultraviolet rays through the wiring lines. Instead of using one wide wiring line, a plurality of wiring lines each having a small width are connected in parallel to one another. The area the wiring lines around a pixel portion and a driving circuit occupy and the area the sealing member occupies are thus reduced in the display device, whereby the display device can be made smaller.