The soft X-ray beamline source is one of the 6-pole equivalent planar wiggler insertion devices installed on the DAΦNE electron ring, for the vertical beam compaction. This wiggler forces the emission of a wide fan of electromagnetic radiation mostly polarized in the horizontal plane. The typical continuous emitted spectral distribution has a critical wavelength of about 44 Å but a useful soft X-ray flux is achievable up to 4 Å due to the high circulating current. The acceptance of the front-end of the wiggler beamline is about 15 mrad. At about 10 m from the front-end a Au-coated mirror (80 cm long) splits the beamline in two, deflecting part of the beam in the UV beamline. The soft X-rays go through the straight section where as a function of the x-ray energy required a polymide or a very thin Be window guarantees both the machine UHV and a high transmittance.