A semiconductor device includes a semiconductor substrate on which a semiconductor device is formed; first and second pads; a first insulating film which is formed above the semiconductor substrate; a plurality of wiring lines which are embedded in ditches provided in the first insulating film; a second insulating film provided to cover the first insulating film and the plurality of wiring lines; a semiconductor layer formed on the second insulating film; a source electrode connected with the semiconductor layer; and a drain electrode connected with the semiconductor layer. The plurality of wiring lines includes a gate electrode provided in a position which is opposite to the semiconductor layer. The semiconductor layer, the source electrode, the drain electrode and the gate electrode configure an ESD protection device to discharge a current by ESD surge from the first pad to the second pad.