This study examined the crystallization of vanadate glasses by using microwave irradiation. A second aim was comparing the thermoelectric properties of crystallized glasses when using microwave irradiation to conventional heating. V2O5-P2O5-Fe2O3-CuO glasses were prepared by using the melt quenching method. These glasses were irradiated by 2.45-GHz microwaves and heated in an electric furnace. MxV2O5 (M= Cu, Fe x=0.26-055) crystals were selectively precipitated by using the microwave irradiation. The crystal growth was also promoted by it. As a result, precipitation crystals formed a fiber-like structure. The electrical conductivity of the microwave irradiated glass was 6.3×101S/m at room temperature, which was three times higher than the value of conventionally-heated glass. The Seebeck coefficient of the microwave irradiated glass was -127 μV/K at room temperature, which was two times higher than that of conventionally-heated glass. This caused the power factor to be improved about 12 times. These results show that microwave irradiation is a potential candidate for obtaining conductive crystallized vanadate glasses.