Rapid sintering of Yb2O3-added AlN was performed by applying the 28 GHz millimeter-wave heating method. It was found that full densification over 97%T.D. was attained by sintering at 1600degreesC for 20 min. The densification temperature was decreased by about 300degreesC, compared with those in the conventional method by an electric furnace. A high thermal conductivity over 180 W/(m . K) was obtained in the sample sintered at 1700degreesC for 40 min, even under non-reducing atmosphere. The main factor resulting in the rapid and low temperature sintering was attributed to efficient selective absorption of the millimeter-wave into Yb2O3 additive. (C) 2003 Kluwer Academic Publishers.