Directional selectivity of microwave magnetic (H) field heating of Au thin films and Si plates was investigated at the H maximum in a single-mode cavity. The surfaces of the specimens were placed either perpendicular or parallel (two orientations) to the H field. The samples with the surfaces perpendicular to H field were heated much easier than those with parallel orientation. The factors related with the heating behavior of these specimens were discussed, considering the distribution of electromagnetic field in the cavity. It was inferred that surface orientation perpendicular to the H field was preferable for inducing eddy current in the specimen surface and resulted in better heating efficiency. (C) 2009 Elsevier B.V. All rights reserved.