An iron alloy according to the present invention comprises: Al in an amount of from 3 to 5.5%; Mn in an amount from 0.2 to 6%; and the balance being iron (Fe), and inevitable impurities and/or a modifying element; when the entirety is taken as 100%. Since a high damping factor is obtainable at a low-strain amplitude, this iron alloy demonstrates a stable damping property even in a high-temperature region. Moreover, since the alloying elements are Al and Mn alone, and since their contents are less, the iron alloy according to the present invention is low in cost.