A thin film transistor substrate comprising a thin film transistor, the thin film transistor including: a first gate electrode formed on the substrate; an active layer formed on the first gate electrode; first and second electrodes (152, 154) formed on the active layer; and a second gate electrode formed on the first electrode, the second electrode, and the active layer, wherein the second gate electrode is provided with an opening formed in an area corresponding to a part of the second electrode, wherein the second gate electrode includes: a plurality of sub gate electrodes that are aligned parallel to each other and are formed on a channel area between the first and second electrodes (152, 154); and one or more connection electrodes that are aligned in a direction orthogonal to the plurality of sub gate electrodes and connect the plurality of sub gate electrodes with one another, wherein the opening corresponds to an area between the respective sub gate electrodes; wherein the thin film transistor substrate further includes: a contact portion that is formed of the same material as that of the second gate electrode together with the second gate electrode, is aligned parallel to the sub gate electrodes and protrudes from one of the one or more connection electrodes in a direction that is opposite to a direction, in which the plurality of sub gate electrodes protrude from the one or more connection electrodes, and electrically connects the second gate electrode with the first gate electrode, wherein the thin film transistor further includes a line electrode formed to be extended from the second electrode to electrically connect the thin film transistor with another circuit device, and the connection electrodes are formed to be overlapped with the line electrode. a first gate electrode formed on the substrate; an active layer formed on the first gate electrode; first and second electrodes (152, 154) formed on the active layer; and a second gate electrode formed on the first electrode, the second electrode, and the active layer, wherein the second gate electrode is provided with an opening formed in an area corresponding to a part of the second electrode, wherein the second gate electrode includes: a plurality of sub gate electrodes that are aligned parallel to each other and are formed on a channel area between the first and second electrodes (152, 154); and one or more connection electrodes that are aligned in a direction orthogonal to the plurality of sub gate electrodes and connect the plurality of sub gate electrodes with one another, a plurality of sub gate electrodes that are aligned parallel to each other and are formed on a channel area between the first and second electrodes (152, 154); and one or more connection electrodes that are aligned in a direction orthogonal to the plurality of sub gate electrodes and connect the plurality of sub gate electrodes with one another, wherein the opening corresponds to an area between the respective sub gate electrodes; wherein the thin film transistor substrate further includes: a contact portion that is formed of the same material as that of the second gate electrode together with the second gate electrode, is aligned parallel to the sub gate electrodes and protrudes from one of the one or more connection electrodes in a direction that is opposite to a direction, in which the plurality of sub gate electrodes protrude from the one or more connection electrodes, and electrically connects the second gate electrode with the first gate electrode, wherein the thin film transistor further includes a line electrode formed to be extended from the second electrode to electrically connect the thin film transistor with another circuit device, and the connection electrodes are formed to be overlapped with the line electrode.