Abstract: A chair having a seat and a back rest. The back rest is attached to the seat via a back rest support element. The flat spring can be made from a non-metallic material, such as from fiberglass. The back rest support element comprises a flat spring disposed under pretension. In one embodiment, the seat is disposed upon a seat support structure having four legs. Preferably, the legs are splayed outside the perimeter of the seat, so that the chair is stackable with chairs of like design. The seat and the back rest can be made from a lightweight plastic material, and that the support structure can be made from tubular steel.