PURPOSE: To stabilize threshold voltage, restrain the irregularity of gate capacitance coupling, and shorten the manufacturing process, by restraining the leak current of a TFT which is used as a pixel switching device.

CONSTITUTION: The thin film semiconductor device is composed of a plurality of thin film transistors connected in series, and has multigate structure in which gate electrodes 9 of a plurality of the thin film transistors are connected in common. The gate electrode 9 of at least one transistor out of a plurality of the thin film transistors is offset-arranged to a channel region 2, and an offset region 6 is arranged between the channel region 2 and a source region 3 or a drain region 5.