A foot rest mountable on a motor vehicle floor has a foundation with a mounting surface, a footboard, and a fastening apparatus acting between the foundation and the footboard that holds the footboard on the mounting surface. The fastening apparatus has a lower, first fastening element constructed in the form of a rigid back-reaching element and an upper, second fastening element. For short installation times of the footboard on the foundation, the fastening apparatus is additionally provided with a third fastening element constructed as a rigid back-reaching element, and the upper fastening element is constructed as a slide blocking element that blocks a relative displacement between the footboard and the mounting surface.