The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, has set up a low-energy electron storage ring in close cooperation with the BESSY GmbH in Berlin-Adlershof. The new storage ring, named Metrology Light Source (MLS), will be mainly dedicated to metrology and technological developments in the EUV, VUV, and IR spectral range. The design of three infrared beamlines will take advantage of the high brightness, the high flux, and the broadband behavior of the synchrotron radiation source. Additionally the MLS will be the first dedicated storage ring designed und prepared for the production of coherent synchrotron radiation (CSR) in the FIR and THz region.