To provide a manufacturing method in which a thin-film transistor can be manufactured at low costs by a method wherein a patterning process by a photoresist is reduced in a working process in which a semiconductor layer, a gate electrode and a source-drain electrode are shaped.

A gate electrode 108 and n-type ion shielding films 203, 204 are formed on a semiconductor layer 201 on an insulating substrate 103, and a gate anodic oxide film 109 is formed on the gate electrode 108. Then, n-type ions are implanted, and the n-type ion shielding films 203, 204 are removed owing to a difference in an etching rate from that of the gate anodic oxide film 109. Then, a source-drain electrode 111 is formed, the shape of the semiconductor layer is worked by making use of the planar shape of the gate electrode 108 and the source-drain electrode 111, a source-drain anodic oxide film 113 is formed on the source-drain electrode 111, p-type ion implantation layers 106, 206 are exposed owing to a difference in an etching rate from that of the source-drain anodic oxide film 113, and p-type ions are implanted.