Diamond-like carbon (DLC) films were produced on the surface of a pure iron substrate at room temperature using a pulsed high-density plasma beam from a coaxial plasma gun. DLC films have a wide mixing interlayer with substrates, which can improve their adhesion to the substrates. The plasma density ranged between 10 14 and 10 16 cm −3 , the plasma electron temperature was 10–50 eV, the mean plasma speed 30–50 km s −1 , and the pulse width about 60 μs. Hardness and thickness measurements, a scratch tester, Raman spectroscopy, Auger electron spectroscopy, and X-ray diffraction were used to characterize the DLC films.