In a semiconductor device, where, with respect to a parasitic resistor in a current mirror circuit, a compensation resistor for compensating the parasitic resistor is provided in the current mirror circuit, the current mirror circuit includes at least two thin film transistors. The thin film transistors each have an island-shaped semiconductor film having a channel formation region and source or drain regions, a gate insulating film, a gate electrode, and source or drain electrodes, and the compensation resistor compensates the parasitic resistor of any one of the gate electrode, the source electrode, and the drain electrode. In addition, each compensation resistor has a conductive layer containing the same material as the gate electrode, the source or drain electrodes, or the source or drain regions.