Abstract: A seat back or a seat base of an automobile seat with a frame includes a spring system extending between two opposing cross braces consisting of meander-shaped shaped spring wires and upholstery in a seat surface. The level determined by the supporting surface of the shaped wire springs may be so changed by tension belts passing through the shaped wire springs at different tensions that it is more strongly arched when the belts are in relaxed condition than when they are tightened.