To suppress the occurrence of a failure caused by static electricity in
the manufacturing process of an active matrix type display device in
which an active matrix circuit and peripheral drive circuits are
integrated on a glass substrate, a protective capacitor to be connected
to a short ring is formed using a semiconductor layer made from the same
material as the active layer of a thin film transistor present under the
short ring. This protective capacitor has a function to absorb an
electric pulse generated in the plasma using process. Discharge patterns
are provided to prevent an electric pulse from affecting each circuit.