An arc fault detection device for detecting an arc fault in an electric line includes a first terminal and a second terminal for connecting the arc fault detection device to a conductor of the electric line. A sensor is adapted for generating a sensor signal from a current through the electric line; and a controller is adapted for detecting the arc fault from the sensor signal. The sensor includes an inductor connected to the first terminal and the second terminal and a capacitor connected in parallel with the inductor. The inductor and the capacitor form a resonant circuit with a resonance frequency, the resonance frequency determining an impedance behavior of the resonant circuit; wherein the inductor and the capacitor are chosen such that the impedance behavior of the resonant circuit corresponds to a desired impedance behavior over a relevant frequency range of the current through the electric line.