An active matrix substrate includes a substrate and an insulating unit arranged on the substrate. The substrate includes a display region and a periphery circuit region beside the display region. The periphery circuit region has at least a chip connecting unit. Each chip connecting unit includes a number of connecting elements. Each of the connecting elements includes a conducting pad and a wire electrically connected to the conducting pad. The conducting pads of the connecting elements are arranged in at least two rows. The insulating unit has a number of contact holes corresponding to the conducting pads so that each of the conducting pads is entirely exposed by the corresponding contact hole. The active matrix substrate is applied to a display device to increase reliability of the display device and improve the quality of the display device.