The method and the device serve to adapt the valve characteristic of a fuel injection valve, which has a piezoelectrically driven nozzle needle and by which fuel is injected directly into the combustion chamber of an internal combustion engine, to production-related or age-related variations in the injection behavior. The activation energy and the needle stroke of the fuel injection valve are controlled in such a way that the engine torque in the case of a fuel injection valve with a reference characteristic would not vary. Here, if an actually occurring variation in the engine torque is detected, then by varying the gradient of the activation-energy/valve-stroke characteristic curve of the fuel injection valve, the engine torque is matched to the engine torque generated with an injection valve with a reference characteristic.