Active matrix substrate and manufacturing method thereof

An active matrix substrate comprising:

• a substrate;
• and
• a plurality of oxide semiconductor TFTs supported on the substrate,
• wherein each of the plurality of oxide semiconductor TFTs includes
• an oxide semiconductor layer including a first region and a second region having a specific resistance lower than a specific resistance of the first region, and
• a gate electrode disposed on at least a part of the first region of the oxide semiconductor layer with a gate insulating layer interposed between the gate electrode and the part of the first region of the oxide semiconductor layer,
• the gate insulating layer includes a first insulating layer and a second insulating layer disposed on the first insulating layer, and
• the first insulating layer overlaps with the first region and does not overlap with the second region, and the second insulating layer overlaps with the first region and at least a part of the second region, when viewed from a normal direction of the substrate.