A device for determining the rotational speed of a rotating component, in particular of a brake disc (1) of an automotive vehicle brake, the brake disc (1) containing recesses (2) shaped at preferably regular distances and lying opposite to a probe. A contact element (5) is provided as the probe which is adapted to move into abutment on the brake disc (1) and which, when overriding each recess (2), will interrupt an electric circuit comprising an evaluation circuit.