The present invention refer an fastening device for detachable fixation of a load carrier at a vehicle, comprising a bracket (3) or similar arranged at the roof of the vehicle, which is essentially firmly fixed at the roof, and which having at least an elongated recess (5), hole or similar for detachable clamping of a load carrier foot (1) or similar, which load carrier foot (1) comprises an axially movable bolt (6) or similar, with a head (7) of the bolt having an essential elongated shape, which is intended to be unobstructed introduced along with said recess (5), and through a twist across said recess (5) obtain an axial locking of the bolt (6). The essential for invention is that the elongated recess (5) or the hole having arched longitudinal side edges, whereby said head (7) is admitted to slide along the arched side edges at a movement of the bolt (6) in direction along with the side edges.