An array substrate includes: a substrate; a thin film transistor including a gate electrode, an oxide semiconductor layer and source and drain electrodes, wherein a first insulating layer of an inorganic insulating material is disposed between the gate electrode and the oxide semiconductor layer, and wherein a second insulating layer of an inorganic insulating material is disposed between the oxide semiconductor layer and the source and drain electrodes; a passivation layer on the thin film transistor; a first electrode on the passivation layer in the pixel region; and a first hydrogen absorbing layer on at least one of top and bottom surfaces of the first insulating layer, top and bottom surfaces of the second insulating layer and top and bottom surfaces of the passivation layer, the first hydrogen absorbing layer including plurality of particles spaced apart from each other and including one of nickel, palladium and platinum.