Suspension system comprising a flat spring member having four legs. The legs are symmetrically arranged with respect to the center position of the spring member and each of the legs has a longitudinal axis and an end portion. A suspension frame is provided to support the spring member (by fixing the end portion of two legs. Two preload elements are arranged close to the end portions of two of the legs in a manner to apply a preloading force at those legs. The preloading force essentially points in the direction of the longitudinal axis.