A joining device includes a mobile joining head with a joining tool which is arranged on an industrial robot, an element feed system, and a control device which is configured to activate the joining tool and control the element feed system. The element feed system has a magazine device which is movable with the joining head and which has a working magazine in which a large number of joining elements are accommodatable at a same time and a separating device from which joining elements are conveyable onward from the magazine device in a direction of the joining tool, a stand-by magazine which is stationary and which is fillable with joining elements from a sorting device, and a coupling device that couples the magazine device to the stand-by magazine where a first coupling half is arranged on the magazine device and a second coupling half is arranged on the stand-by magazine.