Fuel injector

The injector has a sleeve-shaped closure (4) for formation of a switching valve chamber (5) and partially receiving a sealing piston (6). The closure is supported at a piezoelectric actuator (2) via a load distribution plate (9), where the load distribution plate and the closure are connected as a single-piece. The closure and the load distribution plate comprise an annular portion and an annular filling body (11) for reducing volume of the switching valve chamber and forming a guide diameter (12) with the sealing piston.