The development of high performance magnetic data storage devices requires the further miniaturization of bit sizes and the shortening of read/write cycles. For these future generations of magnetic data storage devices a fundamental understanding of the magnetization dynamics in nanostructures is indispensable. We realized a novel experimental setup which allows us to study the fundamental limits in magnetization dynamics on nm length scales. We operate a photoemission electron microscope (PEEM) with a fs-laser light source. The fs temporal resolution is achieved by laser based pump-probe techniques and the magnetic sensitivity is obtained by analyzing the spin of the emitted photoelectrons. We will present an application of the technique to CoPt nanoscale magnetic dots [6].