An equiatomic CoCrFeNiMnAl high-entropy alloy was synthesized by mechanical alloying, and alloying behaviors, microstructure and annealing behaviors were investigated. It was found that a solid solution with refined microstructure of 20 nm in grain size could be obtained after 30 h milling. As-milled powder transformed into a face-centered cubic phase above 500 degrees C. The as-milled powder was subsequently consolidated by spark plasma sintering at 800 degrees C, BCC phase and FCC phase coexisted in the consolidated HEA, which had excellent properties in Vickers hardness of 662 HV and compressive strength of 2142 MPa. (C) 2014 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.