Abstract: The invention relates to a fuel injector having an electromagnet 2 which contains a magnet core 6 and a coil 7 and which further has an armature 9 that is guided on an armature pin 8. The armature pin 8 is guided in a guide sleeve 11 which projects into the electromagnet 2. The fuel injector further has an injector body 4 with at least one injection opening which is introduced into the injector body 4 and which is controlled by an injector needle 5. The aim of the invention is to provide a fuel injector which is functionally improved with respect to the switching times of the fuel injector and the forces that can be generated in the fuel injector while simultaneously simplifying a guide sleeve for an armature pin. This is achieved in that the guide sleeve 11 is integrated into the magnet core 6 and is connected to the magnet core 6 in a formfitting or bonded manner.