Provided is a TFT substrate including a dielectric substrate and a plurality of antenna unit regions arranged on the dielectric substrate. The TFT substrate further includes a transmission and/or reception region including the plurality of antenna unit regions, and a non-transmission and/or reception region positioned in a region other than the transmission and/or reception region. Each of the plurality of antenna unit regions is provided with a TFT that is supported by the dielectric substrate and that includes a gate electrode, a semiconductor layer, a gate insulating layer formed between the gate electrode and the semiconductor layer, and a source electrode and a drain electrode-electrically connected to the semiconductor layer; and a patch electrode electrically connected to the drain electrode of the TFT. The patch electrode is formed from the same conductive film as the gate electrode.