A device for driving a load such as an electric motor for driving a fan mounted on an automobile includes a semiconductor power FET for supplying a load current to the load, a voltage detector for detecting a load voltage, a current detector for detecting a load current and a control circuit for controlling an amount of the load current. The load current is limited to a first limiting level when the detected load current exceeds a predetermined current level, and to a second limiting level, which is lower than the first limiting level, when the load current exceeds the predetermined current level and the load voltage becomes lower than a predetermined voltage level. By limiting the amount of load current, the power FET is surely prevented from being damaged by over-current even if a circuit including the load is short-circuited.