<p>An arc plasma source 101 for evaporating a cathode material of a cathode 22 by arc discharge controlled by a magnetic field, comprising a magnetic field forming mechanism 42 arranged outside the cathode for forming a magnetic field M in parallel to the center axis of the cathode near an evaporation surface 22a; a supporting mechanism 26 for supporting the cathode; a cooling mechanism 61 for cooling the cathode; and a tapered ring 64 being truncated cone shaped and having a through-hole into which the cathode penetrates along the axial direction of the through-hole, the tapered ring being arranged to be tapered toward the evaporation surface of the cathode; wherein the tapered ring is made of a ferromagnetic material and the front end of the tapered ring is positioned coplanar with the evaporation surface of the cathode or is positioned posterior to the evaporation surface in use.</p>
