Fuel injection system for direct injection internal combustion engine

A fuel injection system for an internal combustion engine with direct injection includes a fuel injection device which can inject the fuel directly into a combustion chamber of the engine has a valve element bordering on a work chamber, and the position of the valve element depends on the pressure in the work chamber. A pressure booster piston borders on a control chamber on one side and on a high-pressure chamber on the other. A fuel supply can subject the control chamber to various pressures. The pressure booster piston is integrated with the fuel injection device and that the high-pressure chamber is integrated with the work chamber.