To avoid malfunction caused by biting of foreign materials between a valve element and a valve seat, or adhesion of abraded powder in a control device.

A duty ratio of a driving pulse signal is controlled (step 5) according to a target fuel pressure during normal operation (step 2), and an opening of a valve body is regulated. Pressurized fuel is partially leaked through the pressure regulator. When the duty ratio is increased, the fuel pressure is lowered. During deceleration accompanying cutting fuel (step 3), scavenging mode is executed. A scavenging pulse signal of large frequency is transmitted so that large and small liftings of the valve body are repeated (step 8). An ON duty ratio of repetition number of the scavenging pulse signal are set according to the immediately previous operation conditions (step 7). When abnormal lowering of the fuel pressure is sensed, the scavenging mode is immediately executed based on the specified duty ratio and repetition number even without deceleration (step 10).