Polymer microfabrication methods are becoming increasingly important as low-cost alternatives to the silicon or glass-based MEMS technologies. We present in this paper the technology of hot embossing as a flexible, low-cost microfabrication method for polymer microstructures, which uses the replication of a micromachined embossing master to generate microstructures on a polymer substrate. With this fabrication technology high aspect ratio structures can be fabricated over large surface areas, which allows a commercially successful manufacturing of polymer microcomponents.