In the present work, the microwave dielectric ceramic (Ag0.5Bi0.5)(Mn0.5W0.5)O-4 was prepared by using the solid-state reaction method. (Ag0.5Bi0.5)(Mn0.5W0.5)O-4 was found to crystallize in the scheelite structure, in which Ag+ and Bi3+ occupy the A site randomly with 8-coordination while Mo6+ and W6+ occupy the B site with 4-coordination, at a sintering temperature above 500 degrees C, with lattice parameters a = b = 5.29469(2) angstrom and c = 11.62114(0) angstrom, space group I4(1)/a (No. 88), and acceptable R-p = 9.38, R-wp = 11.2, and R-exp = 5.86. High-performance microwave dielectric properties, with permittivity similar to 26.3, Q(f) value similar to 10000 GHz, and temperature coefficient similar to+20 ppm/degrees C, were obtained in the sample sintered at 580 degrees C. Its chemical compatibility with aluminum at its sintering temperature was revealed and confirmed by both X-ray and energy dispersive spectrometer analysis This ceramic could be a good candidate for ultralow-temperature cofired ceramics.