A display device includes an insulating substrate having a display area, a line part including a data line and a gate line insulated from and crossing each other, a common voltage supplying part formed outside an outer circumference of the display area, an insulating layer formed on the common voltage supplying part and including a contact hole formed on an area in which some lines of the line part extend substantially in parallel with each other, and a common electrode electrically connected with the common voltage supplying part exposed through the contact hole.