An interface for controlling at least one function of a unit of a motor vehicle, comprising a display screen (7) and at least one control member (2) comprising a mobile gripping element (2a) that is rotatably mobile about an axis (A), at least two conductive indicators (10) that are borne by the mobile element (2a) and that are mobile together with same and a guide (2b), the interface being characterized in that it comprises a capacitive sensor (6) comprising a plurality of electrodes (12) that are configured to detect a variation in the angular position of the conductive indicators (10) and in that the guide (2b) is at least partly fixed to the display screen (7) such that the mobile element (2a) partially covers the screen, the electrodes (12) being arranged in a contiguous region (6a) of the screen (7), such that the indicators (10) are movable so as to face the electrodes (12) when the mobile element (2a) is moved about its axis.