An exemplary aspect of the present invention is a thin film transistor including: a gate electrode formed on a substrate; a gate insulating film that includes a nitride film and covers the gate electrode; and a semiconductor layer that is disposed to be opposed to the gate electrode with the gate insulating film interposed therebetween, and has a microcrystalline semiconductor layer formed in at least an interface in contact with the nitride film, in which the microcrystalline semiconductor layer contains oxygen at a concentration higher than that of contained nitrogen in at least the vicinity of the interface with the nitride film, the nitrogen being diffused from the nitride film.