Abstract: In door interlock mechanisms, used for locking the door of washing machines or fumble dryers, the closed or open state of the door of the machine is detected by reading the resistive value of a circuit in which a switch is placed in series. The interlock mechanism according to the invention envisages providing the door interlock with two contacts that make it possible to check, independently, whether the device is in the position with the door closed and locked and whether the door catch is inserted in the device. The device comprises an open-door contact, actuated in the closing position by a shaped portion of a first slider and in the opening position by a shaped portion of a second slider which, under the action of elastic means, interacts with the door catch.