An active matrix type liquid crystal display device includes (a) a transparent substrate, (b) a plurality of scanning lines formed on the transparent substrate, (c) a plurality of signal lines formed on the transparent substrate perpendicularly to the scanning lines, (d) a transparent electrode arranged in a pixel area defined by the scanning and signal lines, and (e) a thin film transistor formed in association with the transparent electrode, the thin film transistor being formed in an area at which one of the scanning lines and one of the signal lines intersect with each other, the thin film transistor including source and drain regions both comprised of an electrically conductive film of which the signal lines are comprised.