New conductive glass with a composition of 20BaO·10Fe 2 O 3 · x WO 3 ·(70 −  x )V 2 O 5 ( x  = 10–50) was investigated by means of Mössbauer spectroscopy. A marked decrease in quadrupole splitting (Δ) was observed after the isothermal annealing at 500 °C for 1,000 min, due to the structural relaxation of 3D-network composed of FeO 4 , VO 4 , and VO 5 units. After the isothermal annealing, a marked increase in the electrical conductivity ( σ ) was observed from 1.7 × 10 −5 to 1.0 × 10 −1  S cm −1 when “ x ” was 10, whereas comparable σ values of 1.1 × 10 −4 and 2.0 × 10 −4  S cm −1 were observed when “ x ” was 40. These results evidently show that structural relaxation of 3D-network structure involved with a marked increase in σ is intrinsic of “vanadate glass”. XRD pattern indicated several weak peaks due to needle-like BaFe 2 O 4 and α-Fe 2 O 3 when the glass sample with “ x ” of 20 was annealed at 500 °C for 1,000 min. SEM study proved the formation of needle-like BaFe 2 O 4 just on the surface of the sample, whereas hexagonal BaFe 12 O 19 were observed in the annealed sample with “ x ” of 40. Chemical durability of WO 3 -containing vanadate glass was investigated by immersing each glass sample into 20 %-HCl solution for 72 h.