Transport box, in particular roof box, for a motor vehicle, comprising - a base shell, which is fixed to the vehicle in a ready-to-use mounted state, - a cover shell, which is mounted on the base shell so as to be pivotable about at least one pivot axis and can be displaced relative to the base shell between a closed position, in which the cover shell rests on the base shell while enclosing a transport volume, and an open position, in which the cover shell is displaced about the pivot axis and thereby lifted from the base shell while opening the transport volume, - a locking device by means of which the cover shell can be locked in the closed position on the base shell, - and having at least one articulated support, by means of which the cover shell is supported on the base shell in the open position, and which has at least one first articulated lever, which is mounted on the base shell such that it can move in an articulated manner, and a second articulated lever, which is mounted on the cover shell such that it can move in an articulated manner, - wherein the first articulated lever and the second articulated lever are connected to one another at least indirectly so as to be articulated about an articulation axis and can be displaced relative to one another about the articulation axis by means of a displacement of the cover shell between the closed position and the open position, - wherein a securing device with a securing element is arranged on the at least one articulated support, and in that the at least one securing element is provided to prevent the articulation mobility of the articulated support to lock the articulation axis, - wherein the base shell has a first bearing element, on which the first articulated lever is articulated, and a second bearing element, on which the second articulated lever is articulated, - characterized in that the securing element - in the closed position of the cover shell - engages at one end on the first bearing element and at the other end on the second bearing element and forms a rigid connection between the first bearing element and the second bearing element. - a base shell, which is fixed to the vehicle in a ready-to-use mounted state, - a cover shell, which is mounted on the base shell so as to be pivotable about at least one pivot axis and can be displaced relative to the base shell between a closed position, in which the cover shell rests on the base shell while enclosing a transport volume, and an open position, in which the cover shell is displaced about the pivot axis and thereby lifted from the base shell while opening the transport volume, - a locking device by means of which the cover shell can be locked in the closed position on the base shell, - and having at least one articulated support, by means of which the cover shell is supported on the base shell in the open position, and which has at least one first articulated lever, which is mounted on the base shell such that it can move in an articulated manner, and a second articulated lever, which is mounted on the cover shell such that it can move in an articulated manner, - wherein the first articulated lever and the second articulated lever are connected to one another at least indirectly so as to be articulated about an articulation axis and can be displaced relative to one another about the articulation axis by means of a displacement of the cover shell between the closed position and the open position, - wherein a securing device with a securing element is arranged on the at least one articulated support, and in that the at least one securing element is provided to prevent the articulation mobility of the articulated support to lock the articulation axis, - wherein the base shell has a first bearing element, on which the first articulated lever is articulated, and a second bearing element, on which the second articulated lever is articulated, - characterized in that the securing element - in the closed position of the cover shell - engages at one end on the first bearing element and at the other end on the second bearing element and forms a rigid connection between the first bearing element and the second bearing element.