A fuel injector is described which is able to be preassembled in a receiving opening of a fuel-distributor line in a loss-proof manner in a structural unit in the form of a fuel charge assembly for transport to the final assembly at the vehicle manufacturer. A radial support disk for preventing the loss of the fuel injector is disposed on the inflow-side end of the inlet pipe by press-fitting the radial support disk in the receiving opening. The fuel injector is particularly suitable for the direct injection of fuel into a combustion chamber of a mixture-compressing internal combustion engine having externally supplied ignition.