To loosen fluctuation of fuel pressure in a common rail, and provide stable fuel injection characteristics, by providing a solenoid valve in a fuel return passage from the common rail in which pressure of fuel supplied by a fuel pump is accumulated to a fuel tank, and controlling the solenoid valve to be opened/closed corresponding to a control signal to an injector.

In an accumulator fuel injector 20 in which pressure of fuel supplied from a fuel pump is accumulated in a common rail 7 and ejected from an injector 8, a solenoid valve 21 is arranged on the upstream side of an orifice 17 in a fuel return passage 16, and controlled together with the injector 8 by a control circuit 22. That is, phase is shifted from the control pulse of the injector 8, the control pulse of the solenoid valve 21 is outputted to the solenoid valve 21, and thereby pressure fluctuation by the injector 8 on a pressure side lower than a target pressure in the common rail 7 and pressure fluctuation by the solenoid valve 21 on a pressure side higher than the target pressure are superposed, therefore fluctuation of fuel pressure in the common rail 7 is loosened.