which the lowerable floor seal 16 is fastened to the door leaf 11 fig2 shows that the magnet element 12 is partially accommodated by the groove 13 but when the door is open one part can protrude on the end side in relation to the door leaf 11 the magnet element 12 is fastened to the door leaf for example by a screw 17 the screw 17 can extend through the disc shaped magnet element 12 in the exemplary embodiment according to fig2 a spring 14 for example a spiral spring is also provided the spring 14 surrounding the screw 17 and being disposed in the groove 13 between the magnet element 12 and groove base as a result the magnet element 12 is mounted in a flexibly resilient manner counter to the force of the spring 14 it therefore does not matter if the magnet element 12 protrudes slightly further than shown in the drawing of fig2 tolerances in the spacing between the end side of the door leaf 11 and the door frame against which the sliding door closes can therefore also be compensated for owing to the magnetic force the magnet element 12 is drawn out of the groove 13 if appropriate also counter to the spring force 14 when it passes into the vicinity of the counterpart 21 so that tolerances can also be spanned.