According to one embodiment, provided is a thin film transistor device with further improved area efficiency. First contact regions of a first semiconductor layer portion are formed with the first channel region therebetween in a predetermined direction and doped with an N-type impurity, one of the first contact regions electrically connected with a shared electrode, while the other electrically connected with a first electrode. Second contact regions of a second semiconductor layer portion are formed with the second channel region therebetween in the predetermined direction and doped with a P-type impurity, one of the second contact regions electrically connected with the shared electrode, while the other electrically connected with a second electrode. The first and second contact regions are partially disposed alternately and adjacently in a direction intersecting with the predetermined direction.