A thin film transistor containing at least, a gate electrode, a gate insulating film, an oxide semiconductor layer, source-drain electrode and a passivation film, in this order on a substrate. The oxide semiconductor layer is a laminate containing a first oxide semiconductor layer (IGZTO) and a second oxide semiconductor layer (IZTO). The second oxide semiconductor layer is formed on the gate insulating film, and the first oxide semiconductor layer is formed between the second oxide semiconductor layer and the passivation film. The contents of respective metal elements relative to the total amount of all the metal elements other than oxygen in the first oxide semiconductor layer are as follows; Ga: 8% or more and 30% or less; In: 25% or less, excluding 0%; Zn: 35% or more to 65% or less; and Sn: 5% or more to 30% or less.