A liquid crystal display comprising: an array substrate; a display portion; and a plurality of pixels arranged in the display portion, wherein the array substrate comprises: an insulating substrate; a first conductive layer on the insulating substrate; a first insulating layer on the first conductive layer; a second conductive layer on the first insulating layer; a second insulating layer on the second conductive layer; a third conductive layer on the second insulating layer; a third insulating layer on the third conductive layer; a fourth conductive layer on the third insulating layer; a plurality of bus lines (12, 13) provided in a region corresponding to the display portion; a plurality of lead wires provided outside the region and each connected to a corresponding bus line; a common electrode provided inside and outside the region for supplying a signal in common to the plurality of pixels; a common trunk wiring provided outside the region, for transmitting the signal; and a connection electrode provided outside the region and connecting the common electrode with the common trunk wiring, the common trunk wiring being provided in the first conductive layer, the plurality of lead wires being provided in the second conductive layer above the common trunk wiring, the common electrode being provided in the third conductive layer, and the connection electrode being provided in the fourth conductive layer, wherein the array substrate includes an opening in the third insulating layer outside the region and on the common electrode, and the connection electrode is connected to the common electrode through the opening in the third insulating layer; and wherein the array substrate includes a plurality of contact holes in the first insulating layer and the second insulating layer on the common trunk wiring, the opening in the third insulating layer extends in a strip-like form above the common trunk wiring, and, in a plan view of the array substrate, a part of the common electrode is positioned in the opening in the third insulating layer, characterised in that the common trunk wiring crosses the plurality of lead wires, and in that, in a plan view of the array substrate, the plurality of contact holes in the first insulating layer and the second insulating layer are positioned in the opening in the third insulating layer. an array substrate; a display portion; and a plurality of pixels arranged in the display portion, wherein the array substrate comprises: an insulating substrate; a first conductive layer on the insulating substrate; a first insulating layer on the first conductive layer; a second conductive layer on the first insulating layer; a second insulating layer on the second conductive layer; a third conductive layer on the second insulating layer; a third insulating layer on the third conductive layer; a fourth conductive layer on the third insulating layer; a plurality of bus lines (12, 13) provided in a region corresponding to the display portion; a plurality of lead wires provided outside the region and each connected to a corresponding bus line; a common electrode provided inside and outside the region for supplying a signal in common to the plurality of pixels; a common trunk wiring provided outside the region, for transmitting the signal; and a connection electrode provided outside the region and connecting the common electrode with the common trunk wiring, an insulating substrate; a first conductive layer on the insulating substrate; a first insulating layer on the first conductive layer; a second conductive layer on the first insulating layer; a second insulating layer on the second conductive layer; a third conductive layer on the second insulating layer; a third insulating layer on the third conductive layer; a fourth conductive layer on the third insulating layer; a plurality of bus lines (12, 13) provided in a region corresponding to the display portion; a plurality of lead wires provided outside the region and each connected to a corresponding bus line; a common electrode provided inside and outside the region for supplying a signal in common to the plurality of pixels; a common trunk wiring provided outside the region, for transmitting the signal; and a connection electrode provided outside the region and connecting the common electrode with the common trunk wiring, the common trunk wiring being provided in the first conductive layer, the plurality of lead wires being provided in the second conductive layer above the common trunk wiring, the common electrode being provided in the third conductive layer, and the connection electrode being provided in the fourth conductive layer, wherein the array substrate includes an opening in the third insulating layer outside the region and on the common electrode, and the connection electrode is connected to the common electrode through the opening in the third insulating layer; and wherein the array substrate includes a plurality of contact holes in the first insulating layer and the second insulating layer on the common trunk wiring, the opening in the third insulating layer extends in a strip-like form above the common trunk wiring, and, in a plan view of the array substrate, a part of the common electrode is positioned in the opening in the third insulating layer, characterised in that the common trunk wiring crosses the plurality of lead wires, and in that, in a plan view of the array substrate, the plurality of contact holes in the first insulating layer and the second insulating layer are positioned in the opening in the third insulating layer.