It is an object of the present invention to provide a technique capable of reducing a contact resistance between source and drain electrodes and a channel region. A thin film transistor includes: a first semiconductor layer provided on a first insulation film lying on a gate electrode and adjacent to a partial region that is part of the first insulation film lying on the gate electrode as seen in plan view; a source electrode and a drain electrode sandwiching the partial region therebetween as seen in plan view; a second insulation film having an opening portion provided over the partial region; and a second semiconductor layer provided on the second insulation film. The second semiconductor layer is in contact with the source electrode and the drain electrode, and is in contact with the partial region and the first semiconductor layer through the opening portion of the second insulation film.