YVO 4:Eu 3+ phosphors were prepared using a domestic microwave oven operated at 2.45 GHz with 500 W. The temperature of raw materials with mixtures of Y 2O 3, V 2O 5 and Eu 2O 3 that were irradiated with the microwave increased to about 840 °C within 150 s. Subsequently, the temperature dropped sharply in spite of the continuing microwave irradiation. Measurement of the dielectric loss factor of the raw materials and products at 2.45 GHz at temperatures from 25 °C to 800 °C revealed a high absorption efficiency of microwave energy by V 2O 5, which provided a rapid increase in the raw material's temperature. A low dielectric loss factor observed for YVO 4:Eu engendered a sharp temperature drop after completion of the reaction of Y 2O 3 with V 2O 5.