A TFT substrate includes a dielectric substrate and a plurality of antenna unit regions arranged on the dielectric substrate. Each of the plurality of antenna unit regions includes a TFT, a patch electrode electrically connected to a drain electrode of the TFT, and a patch drain connection section electrically connecting the drain electrode to the patch electrode, and the patch drain connection section includes a conductive portion included in a conductive layer, the conductive layer being closer to the dielectric substrate than a conductive layer including the patch electrode and being either one of a conductive layer including a gate electrode of the TFT or a conductive layer including a source electrode of TFT, the either one being closer to the dielectric substrate than the other.