An assembly comprising double doors for a railroad vehicle and a door switch, the door switch comprising: a first passive component which is arranged to be movable relative to the double doors and a vehicle main body and is biased by one of the doors when said one of the doors moves toward a full-closed position; a second passive component which is arranged to be movable relative to the double doors and the vehicle main body and the first passive component and is biased by the other one of the doors when the other one of the doors moves toward a full-closed position; a detection unit which is configured to output a detection signal when the first passive component and the second passive component take predetermined relative positions; an elastic component which biases the first passive component and the second passive component to prevent the first passive component and the second passive component from taking the predetermined relative positions; the predetermined relative positions being relative positions of the first passive component and the second passive component when the first passive component and the second passive component are biased by the double doors (100a, 100b) against a biasing force of the elastic component and both of the double doors (100a,100b) eventually reach the full-closed positions, characterized in that the door switch comprises a limit switch including the first passive component, the second passive component movably supporting the first passive component, the elastic component provided between the first passive component and the second passive component, and the detection unit which outputs the detection signal when the first passive component moves for a predetermined distance with respect to the second passive component against an elastic force of the elastic component, in that the limit switch is arranged to be movable with respect to the vehicle main body in directions in parallel to a direction of movement of the first passive component with respect to the second passive component, in that, as said one of the doors biases the first passive component and the other one of the doors biases the second passive component, the first passive component moves with respect to the second passive component against the elastic force of the elastic component, and in that a moving distance of the first passive component with respect to the second passive component is equal to the predetermined distance when both of the doors (100a, 100b) reach the full-closed positions. a first passive component which is arranged to be movable relative to the double doors and a vehicle main body and is biased by one of the doors when said one of the doors moves toward a full-closed position; a second passive component which is arranged to be movable relative to the double doors and the vehicle main body and the first passive component and is biased by the other one of the doors when the other one of the doors moves toward a full-closed position; a detection unit which is configured to output a detection signal when the first passive component and the second passive component take predetermined relative positions; an elastic component which biases the first passive component and the second passive component to prevent the first passive component and the second passive component from taking the predetermined relative positions; the predetermined relative positions being relative positions of the first passive component and the second passive component when the first passive component and the second passive component are biased by the double doors (100a, 100b) against a biasing force of the elastic component and both of the double doors (100a,100b) eventually reach the full-closed positions, characterized in that the door switch comprises a limit switch including the first passive component, the second passive component movably supporting the first passive component, the elastic component provided between the first passive component and the second passive component, and the detection unit which outputs the detection signal when the first passive component moves for a predetermined distance with respect to the second passive component against an elastic force of the elastic component, in that the limit switch is arranged to be movable with respect to the vehicle main body in directions in parallel to a direction of movement of the first passive component with respect to the second passive component, in that, as said one of the doors biases the first passive component and the other one of the doors biases the second passive component, the first passive component moves with respect to the second passive component against the elastic force of the elastic component, and in that a moving distance of the first passive component with respect to the second passive component is equal to the predetermined distance when both of the doors (100a, 100b) reach the full-closed positions.