A bumper having a grille mechanism for providing ventilation, wherein the grille mechanism is foldable and enables to provide a step opening for the step by being opened when the user prefers to reach the front part of the vehicle, comprising - at least one fixed grille fixedly arranged on the middle bumper, - at least one step which is positioned on the middle bumper so as to remain between the middle bumper and the fixed grille, and which enables the user to step thereon to reach the front part of the vehicle; - at least one movable grille and characterized by - the movable grille, which is connected to the fixed grille, and which, by making a rotational movement around the central axis from its ends that are connected to the fixed grille, can be opened and closed on the fixed grille, - at least one actuator, which is connected to the fixed grille and the movable grille, moves simultaneously with the moveable grille, can be opened and closed on the fixed grille by making a rotational movement around the central axis from the ends thereof connected to the fixed grille when a force is applied thereon, and forms a step opening for the step when opened together with the moveable grille, - at least one motion lever, which is connected to the moveable grille from one end thereof and to the actuator from the other end thereof, and which, when the moveable grille and the actuator are being opened and closed, enables them to trigger each other's movement and enables the moveable grille to be opened and closed together with the actuator simultaneously during opening and closing of the actuator on the fixed grille, - at least one resilient member, which prevents the moveable grille and the actuator on the fixed grille from being closed without exertion of a force when they are open and prevents them from being opened without exertion of a force when they are closed wherein - the fixed grille, which comprises an upper connection plate (2.1) and a lower connection plate (2.2) and is fixed to the middle bumper such that the step opening is provided above the step, and to which the movable grille and the actuator are connected so as to open and close the step opening. - at least one fixed grille fixedly arranged on the middle bumper, - at least one step which is positioned on the middle bumper so as to remain between the middle bumper and the fixed grille, and which enables the user to step thereon to reach the front part of the vehicle; - at least one movable grille and characterized by - the movable grille, which is connected to the fixed grille, and which, by making a rotational movement around the central axis from its ends that are connected to the fixed grille, can be opened and closed on the fixed grille, - at least one actuator, which is connected to the fixed grille and the movable grille, moves simultaneously with the moveable grille, can be opened and closed on the fixed grille by making a rotational movement around the central axis from the ends thereof connected to the fixed grille when a force is applied thereon, and forms a step opening for the step when opened together with the moveable grille, - at least one motion lever, which is connected to the moveable grille from one end thereof and to the actuator from the other end thereof, and which, when the moveable grille and the actuator are being opened and closed, enables them to trigger each other's movement and enables the moveable grille to be opened and closed together with the actuator simultaneously during opening and closing of the actuator on the fixed grille, - at least one resilient member, which prevents the moveable grille and the actuator on the fixed grille from being closed without exertion of a force when they are open and prevents them from being opened without exertion of a force when they are closed wherein - the fixed grille, which comprises an upper connection plate (2.1) and a lower connection plate (2.2) and is fixed to the middle bumper such that the step opening is provided above the step, and to which the movable grille and the actuator are connected so as to open and close the step opening.