A TFT substrate (101) including a plurality of antenna element regions (U) arranged on a dielectric substrate (1), the TFT substrate including a transmitting/receiving region including a plurality of antenna element regions, and a non-transmitting/receiving region located outside of the transmitting/receiving region, each of the plurality of antenna element regions (U) including: a thin film transistor (10); a first insulating layer (11) covering the thin film transistor and having a first opening (CH1) which exposes a drain electrode (7D) of the thin film transistor (10); and a patch electrode (15) formed on the first insulating layer (11) and in the first opening (CH1), and electrically connected to the drain electrode (7D) of the thin film transistor, wherein the patch electrode (15) includes a metal layer, and a thickness of the metal layer is greater than a thickness of a source electrode (7S) and the drain electrode (7D) of the thin film transistor.