Abstract Paramagnetic resonance measurements were performed on the Eu 2+ ion in the semiconducting compound EuB 6. Well-defined single-line spectra were obtained at 9.076 4 GHz on pressed, powdered samples at 77, 195, and 295°K. A description is given of an analysis technique, utilizing a programmable calculator, in which the spectra were accurately reproduced by a linear combination of Lorentzian absorption and dispersion susceptibility components. Demagnetizing effects were clearly apparent in the data and required that corrections be applied to obtain the g factor of 2.004±0.001. The observed half-power linewidths were 1724, 1516, and 1494 Oe at 77, 195, and 295°K, respectively. This temperature dependence of Δ H was also attributed to demagnetizing effects so that an extrapolated half-power linewidth of 1477 Oe was obtained.