A thin film transistor includes a substrate, and a pair of source/drain electrodes (i.e., a source electrode and a drain electrode) formed on the substrate and defining a gap therebetween. A pair of low resistance conductive thin films are provided such that each coats at least a part of one of the source/drain electrodes. The low resistance conductive thin films define a gap therebetween. An oxide semiconductor thin film layer is continuously formed on upper surfaces of the pair of low resistance conductive thin films and extends along the gap defined between the low resistance conductive thin films so as to function as a channel. Side surfaces of the oxide semiconductor thin film layer and corresponding side surfaces of the low resistance conductive thin films coincide with each other in a channel width direction of the channel.