In the case of a fuel injector comprising an injector housing arrangement (44, 46) which accommodates a piezo-drive, whereby the piezo-drive has a piezo-actuator which is accommodated in a piezo-housing arrangement that has a cover arrangement (12, 14) provided with openings (16) for the penetration of protruding terminal pins (10) of the piezo-actuator, the following is provided: a sealing arrangement comprising a sealing element (24) formed from a liquid-tight material, the sealing element, on the one hand, fitting tightly against the circumferential areas of the terminal pins (10) and, on the other hand, tightly against the cover arrangement (12, 14), and a ventilation arrangement (40, 42) that promotes an exchange of gas between the outside of the injector housing arrangement (44, 46) and the outside of the sealing element (24).