Hot embossing is the technique to fabricate high precision and high quality plastic microstructures. Industrial fabrication of plastics components is normally achieved by injection molding. Hot embossing is actually used only for a few optical applications where high precision and high quality are important. The advantages of hot embossing are low material flow, avoiding internal stress which induces e.g. scattering centers infavorable for optical applications, and low flow rates, so more delicate structures can be fabricated, such as free standing thin columns or narrow oblong walls. The development of modular molding equipment, orientated on industrial standards has opened the door to the fabrication of plastic microcomponents in great numbers (for example LIGA-UV/VIS-spectrometers). Hot embossing has the potential of increasing production rates and therefore decreasing production costs by the enlargement of the molding surface and automatization of the molding process.