The temperature dependence of the Landau–Lifshitz damping parameter for pure iron has been obtained over the temperature range 290–800 K from the observed amplitude of 73‐GHz microwave radiation transmitted through thin single‐crystalline slabs, approximately 45 &mgr;m thick, at an applied magnetic field corresponding to ferromagnetic antiresonance (FMAR). FMAR occurs when the internal flux densityBsatisfies the conditionB=&ohgr;/&ggr;, where &ohgr; is the circular frequency of the microwave radiation and &ggr; is the gyromagnetic ratio. An applied magnetic field parallel with the specimen plane was used. The Landau–Lifshitz damping parameter was found to increase slowly and monotonically with temperature from the room‐temperature value (0.70 ± 0.06) × 108Hz to (0.86 ± 0.06)× 108Hz at 800 K.