A thin film transistor array substrate is provided. The substrate includes an insulating substrate, a first signal line formed on the insulating substrate, a first insulating layer formed on the first signal line, a second signal line formed on the first insulating layer while crossing over the first signal line, a thin film transistor connected to the first and the second signal lines, a second insulating layer formed on the thin film transistor, the second insulating layer having dielectric constant about 4.0 or less, and the second insulating layer having a first contact hole exposing a predetermined electrode of the thin film transistor, and a first pixel electrode formed on the second insulating layer while being connected to the predetermined electrode of the thin film transistor through the first contact hole.