According to one embodiment, a semiconductor switch circuit includes a semiconductor substrate, an insulating film, a semiconductor layer, a first wiring line, a semiconductor switch unit, and a first conductor. The insulating film is provided on the semiconductor substrate. The semiconductor layer is provided on the insulating film. The first wiring line is provided above the insulating film. The semiconductor switch unit is provided on the semiconductor layer and is electrically connected to the first wiring line. The first conductor is provided between the first wiring line and the semiconductor substrate.