Low-density plasma is generated in a cylindrical DC magnetron discharge tube. The radial and axial distributions of the magnetic field strengths are drawn. The discharge current and voltage (Ia-Va) characteristic curves of the glow discharge have been measured for Ar and He gases pressures. The effect of the applied magnetic field on the (Ia-Va) characteristic curves and on the cathode fall thickness is discussed. The breakdown potentials (VB) of the discharge are lower when the magnetic field is applied.