Zn2GeO4 ceramic materials were synthesized by the solid-state method. Zn2GeO4 powders were investigated with X-ray powder diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). Oxygen defects in the Zn2GeO4 ceramics were investigated by photoluminescence, Raman, and EDS spectra. Conductivity of Zn2GeO4 was 0.18 S/cm at low temperature of 773 K, and its activation energy was 0.49 eV. The results showed that Zn2GeO4 was a promising low-temperature electrolyte with high conductivity.