The invention relates to a child seat for attaching to a motor vehicle seat, comprising a seat element as well as at least one support leg for supporting the child seat on a ground surface, in particular the footwell of the motor vehicle, wherein a display device is provided that is designed to display a ground contact of the support leg with the ground surface, in particular footwell, wherein the support leg has at least one upper telescopic section and a lower telescopic section, which can be moved against one another for lengthening and shortening the support leg, wherein an operative connection is present between the lower telescopic section and the display device, which is designed such that a shifting of the lower section in relation to the upper section leads to a releasing of the display device due to a ground contact of a support leg end.