An alternative oxide anode material to surpass Ni electrode in the solid oxide fuel cell (SOFC) technology, used at high temperature range (500–1000 °C), is needed for the SOFC industry. We investigated an advanced perovskite oxide electrode, CaVxO3-δ system, for the alternative oxide anode material. The CaVxO3-δ powder and bulk were fabricated by using an atmosphere controlled solid-state reaction method and spark plasma sintering (SPS), respectively. The bulk specimen showed 3-3 type nonstoichiometric composite structure, and the electrical conductivity and Seebeck coefficient measurements revealed metallic n-type conductivity. Surprisingly, the high electrical conductivity (> 12,000 S/cm at room temperature; >1000 S/cm at 1000 K) was stable at different atmospheres between air and reduction atmospheres, attributing to a non-redoxable electron-cloud-channel phase protected by a redoxable protection phase. It is believed that the CaVxO3-δ system can be used as a promising and atmosphere stable oxide electrode in the fuel cell technology and other applications.