An electromechanical latch actuation device intended to be mounted on a face of a leaf equipped with a latch , the electromechanical latch actuation device comprising: - a coupling mechanism movable in rotation capable of being secured in rotation with a rotor of a latch cylinder of the latch , - an actuator comprising an electric motor and making it possible to electrically drive in rotation the coupling mechanism , - an operating button movable in rotation adapted for a manual grip and allowing the coupling mechanism to be manually driven in rotation, electromechanical latch actuation device in which the coupling mechanism comprises on the one hand a rotational drive part capable of being coupled in rotation in a reversible manner with a key inserted in the rotor of the latch cylinder and comprising first rotational coupling elements capable of cooperating with the key in a manner making the key and the rotational drive part secured in rotation about the axis of rotation of the rotational drive part , on the other hand a connecting part capable of constituting an intermediate adapter between the rotational drive part and a coupling member of the rotor of the latch cylinder projecting from the rotor of the latch cylinder , in which the connecting part is capable of being coupled in rotation in a reversible manner with the rotational drive part and comprises second rotational coupling elements capable of cooperating, when the connecting part is coupled with the rotational drive part , with the first rotational coupling elements to make the connecting part and the rotational drive part secured in rotation about the axis of rotation of the rotational drive part , in which the connecting part comprises third rotational coupling elements capable of cooperating with the coupling member of the rotor of the latch cylinder in a manner making the coupling member and the connecting part secured in rotation about the axis of rotation of the rotational drive part . - a coupling mechanism movable in rotation capable of being secured in rotation with a rotor of a latch cylinder of the latch , - an actuator comprising an electric motor and making it possible to electrically drive in rotation the coupling mechanism , - an operating button movable in rotation adapted for a manual grip and allowing the coupling mechanism to be manually driven in rotation, electromechanical latch actuation device in which the coupling mechanism comprises on the one hand a rotational drive part capable of being coupled in rotation in a reversible manner with a key inserted in the rotor of the latch cylinder and comprising first rotational coupling elements capable of cooperating with the key in a manner making the key and the rotational drive part secured in rotation about the axis of rotation of the rotational drive part , on the other hand a connecting part capable of constituting an intermediate adapter between the rotational drive part and a coupling member of the rotor of the latch cylinder projecting from the rotor of the latch cylinder , in which the connecting part is capable of being coupled in rotation in a reversible manner with the rotational drive part and comprises second rotational coupling elements capable of cooperating, when the connecting part is coupled with the rotational drive part , with the first rotational coupling elements to make the connecting part and the rotational drive part secured in rotation about the axis of rotation of the rotational drive part , in which the connecting part comprises third rotational coupling elements capable of cooperating with the coupling member of the rotor of the latch cylinder in a manner making the coupling member and the connecting part secured in rotation about the axis of rotation of the rotational drive part . <EOS>