An active matrix substrate includes a plurality of source bus lines and a plurality of gate bus lines and a plurality of oxide semiconductor TFTs that have a plurality of pixel TFTs, each of which is associated with one of the plurality of pixel regions, and a plurality of circuit TFTs constituting a peripheral circuit, in which each of oxide semiconductor TFTs has an oxide semiconductor layer and a gate electrode disposed on a channel region of the oxide semiconductor layer via a gate insulating layer, the plurality of oxide semiconductor TFTs have a plurality of first TFTs, a plurality of second TFTs, and/or a plurality of third TFTs, and the plurality of first TFTs have the plurality of pixel TFTs, and the plurality of second TFTs and/or the plurality of third TFTs have at least a portion of the plurality of circuit TFTs.