A display apparatus includes a substrate, a buffer layer located on the substrate, a first thin-film transistor located on the buffer layer, the first thin-film transistor including a first semiconductor layer and a first gate electrode insulated from the first semiconductor layer. The first semiconductor layer includes an oxide semiconductor. A first inorganic insulating layer is located between the first semiconductor layer and the first gate electrode, and emits at least 1×1019 mole/cm3 of hydrogen (H2).