To provide a footboard for a steel stair which can be used irrespective of the thickness of a small vertical wall, and generates no play even it is installed on a step.

A footboard 10 to be used for a steel stair 1 in which a vertical wall 4 leading to a next upper step is erected on a base end side of a step 3 and a small vertical wall 5 lower than the vertical wall is erected on a forward end side opposite thereto, comprises footboard bodies 11, 12, 13 having the width L smaller than the dimension between the vertical wall and the small vertical wall, and an elastic body 15 which is provided on the footboard body and holds the footboard body between the vertical wall and the small vertical wall without play. A projection 15 is urged by a spring, and fitted in a cylinder 12 in a freely advancing/retracting manner.