According to one embodiment, a semiconductor switch includes a voltage generator, a driver, a switch section, and a power supply controller. The voltage generator is configured to generate a first potential and a negative second potential. The first potential is higher than a power supply voltage supplied to a power supply terminal. The driver is connected to an output of the voltage generator and is configured to output the first potential in response to input of high level and to output the second potential in response to input of low level. The switch section is configured to switch connection between terminals in response to an output of the driver. The power supply controller is configured to control the output of the voltage generator.