A semiconductor-switch control device includes a controller that detects an analog signal of a load current, converts the detected analog signal into a digital signal, and determines an over-current based on the converted digital signal; a short circuit detector that detects an analog signal of a load voltage, and detects an over-current based on the analog signal without converting the detected analog signal into a digital signal; and a drive unit that drives an FET based on a determination result of the over-current determined by the controller or a detection result of the over-current detected by the short circuit detector.